231131130021 has 80 divisors (see below), whose sum is σ = 381687007680. Its totient is φ = 138215911680.

The previous prime is 231131130019. The next prime is 231131130119. The reversal of 231131130021 is 120031131132.

231131130021 is a `hidden beast` number, since 2 + 31 + 1 + 311 + 300 + 21 = 666.

231131130021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 231131130021 - 2¹ = 231131130019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231131129976 and 231131130003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231131130011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 41470591 + ... + 41476163.

It is an arithmetic number, because the mean of its divisors is an integer number (4771087596).

Almost surely, 2^231131130021 is an apocalyptic number.

It is an amenable number.

231131130021 is a deficient number, since it is larger than the sum of its proper divisors (150555877659).

231131130021 is a wasteful number, since it uses less digits than its factorization.

231131130021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6208 (or 6199 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 231131130021 its reverse (120031131132), we get a palindrome (351162261153).

The spelling of 231131130021 in words is "two hundred thirty-one billion, one hundred thirty-one million, one hundred thirty thousand, twenty-one".