31981458861 has 24 divisors (see below), whose sum is σ = 51757059744. Its totient is φ = 18858843360.

The previous prime is 31981458857. The next prime is 31981458953. The reversal of 31981458861 is 16885418913.

It is a happy number.

31981458861 is a `hidden beast` number, since 31 + 9 + 81 + 458 + 86 + 1 = 666.

It is not a de Polignac number, because 31981458861 - 2² = 31981458857 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31981458798 and 31981458807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31981458841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4361811 + ... + 4369136.

It is an arithmetic number, because the mean of its divisors is an integer number (2156544156).

Almost surely, 2^31981458861 is an apocalyptic number.

It is an amenable number.

31981458861 is a deficient number, since it is larger than the sum of its proper divisors (19775600883).

31981458861 is a wasteful number, since it uses less digits than its factorization.

31981458861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8731001 (or 8730998 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 54.

The spelling of 31981458861 in words is "thirty-one billion, nine hundred eighty-one million, four hundred fifty-eight thousand, eight hundred sixty-one".