131891 has 2 divisors, whose sum is σ = 131892. Its totient is φ = 131890.

The previous prime is 131861. The next prime is 131893. The reversal of 131891 is 198131.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131891 is a prime.

Together with 131893, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (131893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65945 + 65946.

It is an arithmetic number, because the mean of its divisors is an integer number (65946).

2¹³¹⁸⁹¹ is an apocalyptic number.

131891 is a deficient number, since it is larger than the sum of its proper divisors (1).

131891 is an equidigital number, since it uses as much as digits as its factorization.

131891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 23.

The square root of 131891 is about 363.1680051987. The cubic root of 131891 is about 50.9024149602.

The spelling of 131891 in words is "one hundred thirty-one thousand, eight hundred ninety-one".