231289931 has 2 divisors, whose sum is σ = 231289932. Its totient is φ = 231289930.

The previous prime is 231289921. The next prime is 231289973. The reversal of 231289931 is 139982132.

231289931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231289931 - 2¹⁰ = 231288907 is a prime.

It is a super-2 number, since 2×231289931² = 106990064363969522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (231289921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115644965 + 115644966.

It is an arithmetic number, because the mean of its divisors is an integer number (115644966).

Almost surely, 2^231289931 is an apocalyptic number.

231289931 is a deficient number, since it is larger than the sum of its proper divisors (1).

231289931 is an equidigital number, since it uses as much as digits as its factorization.

231289931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 38.

The square root of 231289931 is about 15208.2191922657. The cubic root of 231289931 is about 613.8358403144.

The spelling of 231289931 in words is "two hundred thirty-one million, two hundred eighty-nine thousand, nine hundred thirty-one".