ⓘ 113 (number)

113 (number)

ⓘ 113 (number)

  • 113 is the natural number following 112 and preceding 114.
  • 113 is a highly cototient number and a centered square number.
  • It is the 30th prime number following 109 and preceding 127, so it can only be divided by one and itself. 113 is a Sophie Germain prime, a Chen prime and a Proth prime as it is a prime number of the form 7 × 2 4 + 1. 113 is also an Eisenstein prime with no imaginary part and real part of the form 3 n − 1 {\displaystyle 3n-1}. In base 10, this prime is a primeval number, and a permutable prime with 131 and 311.
  • 355/113 approximates pi to six decimal places, with an error of less than 1/113 3. This means that 113/355 approximates the reciprocal of pi.
  • 113 is the smallest positive integer that cannot be represented in the Four fours problem using standard rules.

1. Religion

  • Psalms 113–118 constitute the Hallel, which is recited on the three great feasts: Passover, Weeks, and Tabernacles
  • 113, the number of surah al-Falaq in the Quran

2. Telephony

113 is:

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

3. Other uses

  • 113 band, a French hip hop group
  • 113, the port number of the IDENT Internet protocol that helps identify the user of a particular TCP connection
  • 113, in enduro, is regarded as an unlucky number to be given to a race entrant and is colloquially known as a "blind pew"