113 (number)

113 (one hundred [and] thirteen) is the natural number following 112 and preceding 114. It is a prime number, so it can only be divided by one and itself.

In mathematics

113 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 . 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 six decimal places, with an error of less than 1/113³. This means that 113/355 approximates the reciprocal of pi.

In telephony

• The fire emergency telephone number in Indonesia
• The medical emergency telephone number in Norway and Latvia
• The police emergency telephone number in Italy, Luxembourg, Slovenia and Vietnam
• The Argentina time telephone number
• The intelligence Agency telephone number in Iran

Music

• 113 (band), a French hip hop group

Other Fields

One hundred [and] thirteen is also:

• The port number of the IDENT Internet protocol that helps identify the user of a particular TCP connection
• Cadmium-113m is a radioisotope and nuclear isomer with a halflife of 14.1 years
• The atomic number of an element temporarily called ununtrium.
• In enduro, it is regarded as an unlucky number to be given to a race entrant and is colloquially known as a "blind pew"
• The number of surat al-Falaq in the Qur'an.
• Psalms 113–118 constitute the Hallel, which is recited on the three great feasts, Passover, Weeks, and Tabernacles

See also

• List of highways numbered 113
• National longevity recordholders
• List of oldest people
• M113

References

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