113 (NUMBER)

'113' is the natural number following 112 and preceding 114.

Cardinal	one hundred [and] thirteen
Ordinal	113th
Factorization	''prime''
Roman numeral	CXIII
Binary	1110001
Hexadecimal	71

Contents

In mathematics

In other fields

References

In mathematics

'One hundred [and] thirteen' is the 30th prime number, following 109 and preceding 127, a Sophie Germain prime, a Chen prime and a Proth prime as it is a prime number of the form 7 × 2⁴ + 1. 113 is an Eisenstein prime with no imaginary part and real part of the form $3n\; -\; 1$. In base 10, this prime is a primeval number, and a permutable prime with 131 and 311.
It is a highly cototient number and a centered square number.
355/113 approximates pi to seven decimal places, with an error of less than 1/113³.

In other fields

★ The year AD 113 or 113 BC.

★ The atomic number of an element temporarily called ununtrium.

★ The number of surat al-Falaq in the Qur'an.

★ The emergency telephone number in Italy.

★ The medical emergency telephone number in Norway.

★ Part of an in-joke on some Disney movies. See A113.

★ The French hip hop group 113.

★ The official time telephone number in Argentina. See Argentine telephone numbering plan.

References

★ Wells, D. ''The Penguin Dictionary of Curious and Interesting Numbers'' London: Penguin Group. (1987): 134