231500031 has 16 divisors (see below), whose sum is σ = 357014784. Its totient is φ = 130690944.

The previous prime is 231500029. The next prime is 231500039. The reversal of 231500031 is 130005132.

It is a happy number.

It is not a de Polignac number, because 231500031 - 2¹ = 231500029 is a prime.

It is a super-2 number, since 2×231500031² = 107184528706001922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231500039) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64666 + ... + 68151.

It is an arithmetic number, because the mean of its divisors is an integer number (22313424).

Almost surely, 2^231500031 is an apocalyptic number.

231500031 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

231500031 is a deficient number, since it is larger than the sum of its proper divisors (125514753).

231500031 is a wasteful number, since it uses less digits than its factorization.

231500031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132910.

The product of its (nonzero) digits is 90, while the sum is 15.

The square root of 231500031 is about 15215.1250734261. The cubic root of 231500031 is about 614.0216502178.

Adding to 231500031 its reverse (130005132), we get a palindrome (361505163).

The spelling of 231500031 in words is "two hundred thirty-one million, five hundred thousand, thirty-one".