31900720392 has 48 divisors (see below), whose sum is σ = 86468323500. Its totient is φ = 10624891776.

The previous prime is 31900720387. The next prime is 31900720393. The reversal of 31900720392 is 29302700913.

It can be written as a sum of positive squares in 2 ways, for example, as 31501280196 + 399440196 = 177486^2 + 19986^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (31900720393) 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 11 ways as a sum of consecutive naturals, for example, 91767 + ... + 268742.

Almost surely, 2^31900720392 is an apocalyptic number.

It is an amenable number.

31900720392 is an abundant number, since it is smaller than the sum of its proper divisors (54567603108).

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

31900720392 is a wasteful number, since it uses less digits than its factorization.

31900720392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361750 (or 361743 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The spelling of 31900720392 in words is "thirty-one billion, nine hundred million, seven hundred twenty thousand, three hundred ninety-two".