231131520 has 96 divisors (see below), whose sum is σ = 798145920. Its totient is φ = 61633536.

The previous prime is 231131471. The next prime is 231131521. The reversal of 231131520 is 25131132.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 231131493 and 231131502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231131521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14304 + ... + 25823.

It is an arithmetic number, because the mean of its divisors is an integer number (8314020).

Almost surely, 2^231131520 is an apocalyptic number.

231131520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231131520 is an abundant number, since it is smaller than the sum of its proper divisors (567014400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

231131520 is a wasteful number, since it uses less digits than its factorization.

231131520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40152 (or 40137 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 231131520 is about 15203.0102282410. The cubic root of 231131520 is about 613.6956691204.

Adding to 231131520 its reverse (25131132), we get a palindrome (256262652).

The spelling of 231131520 in words is "two hundred thirty-one million, one hundred thirty-one thousand, five hundred twenty".