# 131 (number)

 ← 130 131 132 →
Cardinal one hundred and thirty-one
Ordinal 131st
(one hundred and thirty-first)
Factorization prime
Prime 32nd
Divisors 1, 131
Roman numeral CXXXI
Binary 100000112
Ternary 112123
Quaternary 20034
Quinary 10115
Senary 3356
Octal 2038
Duodecimal AB12
Vigesimal 6B20
Base 36 3N36

131 is the natural number following 130 and preceding 132.

## In mathematics

131 is a Sophie Germain prime, the second 3-digit palindromic prime, and also a permutable prime with 113 and 311. It can be expressed as the sum of three consecutive primes, 131 = 41 + 43 + 47. 131 is an Eisenstein prime with no imaginary part and real part of the form $3n - 1$. Because the next odd number, 133, is a semiprime, 131 is a Chen prime.

131 is a full reptend prime in base 10. The decimal expansion of 1/131 repeats the digits 00763358778625954198473282442748091603053435114503816793893129770992366412213 74045801526717557251908396946564885496183206106870229 indefinitely.

131 is also: