231131031220 has 24 divisors (see below), whose sum is σ = 485679162024. Its totient is φ = 92394508416.

The previous prime is 231131031193. The next prime is 231131031251. The reversal of 231131031220 is 22130131132.

It can be written as a sum of positive squares in 4 ways, for example, as 4214087056 + 226916944164 = 64916^2 + 476358^2 .

It is a super-2 number, since 2×231131031220² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3586267 + ... + 3650146.

It is an arithmetic number, because the mean of its divisors is an integer number (20236631751).

Almost surely, 2^231131031220 is an apocalyptic number.

231131031220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231131031220 is an abundant number, since it is smaller than the sum of its proper divisors (254548130804).

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

231131031220 is a wasteful number, since it uses less digits than its factorization.

231131031220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7238019 (or 7238017 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 231131031220 its reverse (22130131132), we get a palindrome (253261162352).

It can be divided in two parts, 2311310 and 31220, that added together give a triangular number (2342530 = T₂₁₆₄).

The spelling of 231131031220 in words is "two hundred thirty-one billion, one hundred thirty-one million, thirty-one thousand, two hundred twenty".