6 (number)
6


List of numbers — Integers 

Cardinal  6 six 
Ordinal  6th sixth 
Numeral system  senary 
Factorization  
Divisors  1, 2, 3, 6 
Roman numeral  VI 
Roman numeral (Unicode)  Ⅵ, ⅵ 
Arabic  ٦ 
Arabic (Urdu)  ۶ 
Amharic  ፮ 
Bengali  ৬ 
Chinese numeral  六，陆 
Devanāgarī  ६ 
Hebrew  ו (Vav) 
Khmer  ៦ 
Thai  ๖ 
prefixes  hexa/hex (from Greek) 
Binary  110 
Octal  6 
Duodecimal  6 
Hexadecimal  6 
6 (six) is a number, numeral, and glyph that represents the number. It is the natural number^{[1]} that follows 5 and precedes 7. It is an integer and a cardinal number, that is, a number that is used for counting.^{[2]} In addition, it is classified as a real number,^{[3]} distinguishing it from imaginary numbers.
Contents 
Evolution of the glyph
The evolution of our modern glyph for 6 appears rather simple when compared with that for the other numerals. Our modern 6 can be traced back to the Brahmins of India, who wrote it in one stroke like a cursive lowercase e rotated 45 degrees clockwise. Gradually, the upper part of the stroke (above the central squiggle) became more curved, while the lower part of the stroke (below the central squiggle) became straighter. The Ghubar Arabs dropped the part of the stroke below the squiggle. From there, the European evolution to our modern 6 was very straightforward, aside from a flirtation with a glyph that looked more like an uppercase G.^{[4]}
On the sevensegment displays of calculators and watches, 6 is usually written with six segments. Some historical calculator models use just five segments for the 6, by omitting the top horizontal bar. This glyph variant has not caught on. For calculators that can display results in hexadecimal, a 6 that looks like a B is not practical.
Just as in most modern typefaces, in typefaces with text figures the 6 character usually has an ascender, for example, in .
This numeral resembles an inverted 9. To disambiguate the two on objects and documents that could be inverted, the 6 has often been underlined, both in handwriting and on printed labels.
In mathematics
Six is the second smallest composite number, its proper divisors being 1, 2, and 3. Since six equals the sum of these proper divisors, six is a perfect number. As a perfect number, 6 is related to the Mersenne prime 3, since 2^{1}(2^{2}  1) = 6. (The next perfect number is 28.) Six is the only number that is both the sum and the product of three consecutive positive numbers.^{[5]}
Six is a unitary perfect number, a harmonic divisor number and a highly composite number. The next highly composite number is 12.
5 and 6 form a RuthAaron pair under either definition.
The smallest nonabelian group is the symmetric group S_{3} which has 3! = 6 elements.
S_{6}, with 720 elements, is the only finite symmetric group which has an outer automorphism. This automorphism allows us to construct a number of exceptional mathematical objects such as the S(5,6,12) Steiner system, the projective plane of order 4 and the HoffmanSingleton graph. A closely related result is the following theorem: 6 is the only natural number n for which there is a construction of n isomorphic objects on an nset A, invariant under all permutations of A, but not naturally in 11 correspondence with the elements of A. This can also be expressed category theoretically: consider the category whose objects are the n element sets and whose arrows are the bijections between the sets. This category has a nontrivial functor to itself only for n=6.
Six similar coins can be arranged around a central coin of the same radius so that each coin makes contact with the central one (and touches both its neighbors without a gap), but seven cannot be so arranged. This makes 6 the answer to the twodimensional kissing number problem. The densest sphere packing of the plane is obtained by extending this pattern to the hexagonal lattice in which each circle touches just six others.
6 is the largest of the four allHarshad numbers.
A sixsided polygon is a hexagon, one of the three polygons capable of tiling the plane. Figurate numbers representing hexagons (including six) are called hexagonal numbers. Six is also an octahedral number. It is a triangular number and so is its square (36).
There are six basic trigonometric functions.
There are six convex regular polytopes in four dimensions.
Six is the binary complement of number nine:
6 = 0110 9 = 1001
In numeral systems
Base  Numeral system  

2  binary  110 
3  ternary  20 
4  quaternary  12 
5  quinary  11 
6  senary  10 
over 6 (decimal, hexadecimal)  6 
In base 10, 6 is a 1automorphic number.
List of basic calculations
Multiplication  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  50  100  1000  

6  12  18  24  30  36  42  48  54  60  66  72  78  84  90  96  102  108  114  120  126  132  138  144  150  300  600  6000 
Division  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  

6  3  2  1.5  1.2  1  0.75  0.6  0.5  0.4  
0.5  1  1.5  2  2.5 
Exponentiation  1  2  3  4  5  6  7  8  9  10  11  12  13  

6  36  216  1296  7776  46656  279936  1679616  10077696  60466176  362797056  2176782336  13060694016  
1  64  729  4096  15625  46656  117649  262144  531441  1000000  1771561  2985984  4826809 
In science
 The atomic number of carbon
 The number of carbon atoms and carboncarbon bonds in benzene
 The number of known quarks and leptons
 The number of tastes in traditional Indian Medicine called Ayurveda. They are: sweet, sour, salty, bitter, pungent, and astringent. These tastes are used to suggest a diet based on the symptoms of the body
 The SI prefix for 1000^{6} is exa (E), and for its reciprocal atto (a).
 A hexapod is an animal with six legs; this includes all insects.
Astronomy
 The Roman numeral VI (usually) stands for the sixthdiscovered satellite of a planet or minor planet (such as Jupiter VI).
 The Roman numeral VI stands for subdwarfs in the Yerkes spectral classification scheme.
 The Saros number^{[6]} of the solar eclipse series which began on March 16, 2691 B.C.E. and ended on May 3, 1393 B.C.E. The duration of Saros series 6 was 1298.1 years, and it contained 73 solar eclipses.
 The Saros number^{[7]} of the lunar eclipse series which began on July 25, 2642 B.C.E. and ended on February 10, 1091 B.C.E. The duration of Saros series 6 was 1550.6 years, and it contained 87 lunar eclipses.
In technology
 6 is the resin identification code used in recycling to identify polystyrene
 The "six meter band" in amateur radio includes the frequencies from 50 to 54 MHz
 The audio component of any broadcast channel 6 is located at 87.7 MHz. This means that people can listen to TV stations using an FM radio when a television is not nearby.
 The measuring instrument called a sextant got its name because its shape forms one sixth of a whole circle
 The number of fundamental flight instruments lumped together on a cockpit display, called the sixpack
In religion
Judaism
 According to the biblical book of Genesis, God created man on the sixth day
 There are six points on the Star of David
 Six is the number of orders of the Mishnah
 Six is the number of symbolic foods placed on the Passover Seder Plate
 The Jewish holiday of Shavuot starts on the sixth day of the Hebrew month of Sivan
Christianity
 666 is considered the Number of the Beast
In music
 There are six semitones in a tritone
 There are six strings on a standard guitar
 There are six basic holes or keys on most woodwind instruments (for example, pennywhistle, clarinet, saxophone, bassoon). These holes or keys are usually not given numbers or letters in the fingering charts.
 A group of six musicians is called a sextet
 Six is the number of completed symphonies by Peter Tchaikovsky and Bohuslav Martinů, and the number of Brandenburg Concertos of Johann Sebastian Bach
 The concerti grossi Opus 3, organ concertos Opus 4 and Opus 7 (each) by Georg Frideric Handel
 The number of string quartets of Béla Bartók
 In many cases (usually in rock music) an album's feature track is located on the 6th track of the recording medium
 The French composers Georges Auric, Louis Durey, Arthur Honegger, Darius Milhaud, Francis Poulenc, and Germaine Tailleferre were part of a group known as Les Six ("The Six" in English) in the 1920s
In sports
 In American and Canadian football, six is the number of points received for a touchdown
 In rugby union, six is the position of the blindside flanker
 In rugby league, six is the position of 5/8
 In football (soccer), the number of substitutes combined by both teams, that are allowed in the game
 In baseball, six represents the shortstop's position
 In Australian Rules football, six points are received for a goal
 In cricket, a "six" or "sixer" is a shot in which the ball clears the boundary without bouncing, scoring six runs. Also, there are six balls to an over.
 In ice hockey, there are six players per team, including the goaltender, on the ice at any one time, excluding penalty situations
 The National Hockey League and National Basketball Association are comprised of six divisions each
 In some sports, 6 goals is known as a double hat trick, but it is very hard to accomplish
Miscellany
 In the ancient Roman calendar, Sextilis was the sixth month. After the Julian reform, June became the sixth month and Sextilis was renamed August
 Sextidi was the sixth day of the decade in the French Revolutionary calendar.
 The standard term in office for a United States senator is six years.
 The name of the smallest group of Cub Scouts, traditionally consisting of six boys and is led by a "sixer." However, this is not always the case.
 The number of feet below ground level a coffin is traditionally buried; thus, the phrase "six feet under" means that a person (or thing, or concept) is dead.
 The number of inhabited continents, and the total number of continents if Eurasia (Europe plus Asia) is considered a single continent
 The number of large geyser fields in the world
 The number of sides on a cube, hence the highest number on a standard dice
 The highest number on one end of a standard domino
 The number of dots in a Braille cell
 It is said that there is no more than six degrees of separation between any two people on Earth
 Extrasensory perception is sometimes called the "sixth sense"
 Six Cardinal Directions: North, south, east, west, up, and down
 The Six Dynasties form part of Chinese history
 6 is a lucky number in Chinese culture
 "Six" is used as an informal slang term for the British Secret Intelligence Service, MI6
 In the military, six is used as slang for rear, derived from the position of the number at the bottom of a 12hour clock face, as in "Cover my six."
 The number of Australian states
 Northern Ireland is known as the Six Counties
Hexa is Greek for "six." Thus:
 A hexahedron is a polyhedron with six faces, with a cube being a special case
 An hexagon is a regular polygon with six sides
 L' Hexagone is a French nickname for the continental part of France
 Hexameter is a poetic form consisting of six feet per line
 "Hexadecimal" combines hexa with the Latinate decimal to name a number base of 16
 A "hex nut," of course, is a nut with six sides, and a hex bolt has a sixsided head
 The prefix "hexa" also occurs in the systematic name of many chemical compounds, such as "hexamethyl"
Sex is a Latin prefix meaning "six." Thus:
 Six babies delivered in one birth are sextuplets. The first set of sextuplets of whom all six survived are the Dilley sextuplets.
 People with sexdactyly have six fingers on each hand.
See also
Notes
 ↑ A natural number is any number that is a positive integer, such as 1, 2, 3, 4, and so forth. Often, the number 0 is also called a natural number.
 ↑ A cardinal number indicates the quantity of things, but not the order in which they occur. By contrast, ordinal numbers are first, second, third, and so on, indicating their positions in a series.
 ↑ A real number is a number that can be given by a finite or infinite decimal representation. The term "real number" was coined to distinguish it from an "imaginary number." The set of real numbers includes rational and irrational numbers, which can be positive, negative, or zero.
 ↑ Georges Ifrah, The Universal History of Numbers: From Prehistory to the Invention of the Computer, translated by David Bellos et al (London: The Harvill Press, 1998, ISBN 0471393401).
 ↑ Peter M. Higgins, Number Story: From Counting to Cryptography (London: Copernicus, 2008, ISBN 9781848000001).
 ↑ NASA Eclipse, Solar Eclipses of Saros 0 to 180. Retrieved July 28, 2008.
 ↑ NASA, Lunar Eclipses of Saros Series 1 to 175. Retrieved July 28, 2008.
References
 Cameron, Peter J., and Jacobus Hendricus van Lint. 2000. Designs, Graphs, Codes and Their Links. Cambridge: Cambridge Univ. Press. ISBN 0521423856.
 Flegg, Graham. 2002. Numbers: Their History and Meaning. Mineola, NY: Dover Publications. ISBN 0486421651.
 Higgins, Peter M. 2008. Number Story: From Counting to Cryptography. London: Copernicus. ISBN 9781848000001.
 Ifrah, Georges. 2000. The Universal History of Numbers: From Prehistory to the Invention of the Computer. Translated by David Bellos et al. New York: Wiley. ISBN 0471393401.
 McLeish, John. 1994. The Story of Numbers: How Mathematics Has Shaped Civilization. New York: Fawcett Columbine. ISBN 0449909387.
 Menninger, Karl. 1992. Number Words and Number Symbols: A Cultural History of Numbers. New York: Dover Publications. ISBN 0486270963.
 Wells, D.G. 1998. The Penguin Dictionary of Curious and Interesting Numbers. London: Penguin Books. ISBN 0140261494.
External links
All links retrieved August 8, 2012.
 The Meaning of Numbers: The Number 6 Meaning of Numbers in the Bible.
 The Number 6
 The Significance of The Number Six by Hillel ben David (Greg Killian)
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