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23 (number)

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23 (twenty-three) is the natural number following 22 and preceding 24. It is the smallest natural number with an eleven letter name in English.

Cardinal 23
twenty-three
Ordinal 23rd
twenty-third
Factorizationprime
Roman numeralXXIII
Binary10111
Octal27
Hexadecimal17

In mathematics

Twenty-three is the ninth prime number, the smallest odd prime that is not a twin prime. Twenty-three is also the fifth factorial prime, the second Woodall prime, and the second Smarandache-Wellin prime. It is an Eisenstein prime with no imaginary part and real part of the form [3n - 1].

The fifth Sophie Germain prime and the fourth safe prime, 23 is the next to last member of the first Cunningham chain of the first kind to have five terms (2, 5, 11, 23, 47).

23 also has the distinction of being one of two integers that cannot be expressed as the sum of fewer than 9 cubes of integers (the other is 239). See Waring's problem.

23 is a Wedderburn-Etherington number.

A highly cototient number, 23 is the solution to x - φ(x) for the integers 95, 119, 143, 529.

The codewords in the perfect (non-extended) binary Golay code are of size 23.

In binary, 23 is the smallest prime having a composite sum of digits.

In science

Astronomy

In religion

In numerology

In sports

In other fields

Twenty-three is:

Miscellaneous

Jim Carrey, in People Magazine, April 17, 2006, page 142, is quoted as saying: "I've [been fixated on] the number 23 for years. It's everywhere. Each parent passes on 23 chromosomes; Earth's axis is at a 23° angle. Psalm 23 is my mantra..."

Historical years

23 A.D., 23 B.C., 1923, 2023, etc.

External link

 


From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.

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