231131 has 2 divisors, whose sum is σ = 231132. Its totient is φ = 231130.

The previous prime is 231109. The next prime is 231169. The reversal of 231131 is 131132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231131 - 2⁶ = 231067 is a prime.

It is a super-2 number, since 2×231131² = 106843078322, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (231031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115565 + 115566.

It is an arithmetic number, because the mean of its divisors is an integer number (115566).

2²³¹¹³¹ is an apocalyptic number.

231131 is a deficient number, since it is larger than the sum of its proper divisors (1).

231131 is an equidigital number, since it uses as much as digits as its factorization.

231131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18, while the sum is 11.

The square root of 231131 is about 480.7608553117. The cubic root of 231131 is about 61.3695208889.

Adding to 231131 its reverse (131132), we get a palindrome (362263).

Subtracting from 231131 its reverse (131132), we obtain a palindrome (99999).

The spelling of 231131 in words is "two hundred thirty-one thousand, one hundred thirty-one".