31990392 has 48 divisors (see below), whose sum is σ = 99019440. Its totient is φ = 9139968.

The previous prime is 31990381. The next prime is 31990397. The reversal of 31990392 is 29309913.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31990397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31233 + ... + 32240.

It is an arithmetic number, because the mean of its divisors is an integer number (2062905).

Almost surely, 2^31990392 is an apocalyptic number.

It is an amenable number.

31990392 is an abundant number, since it is smaller than the sum of its proper divisors (67029048).

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

31990392 is a wasteful number, since it uses less digits than its factorization.

31990392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63492 (or 63485 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 31990392 is about 5656.0049504929. The cubic root of 31990392 is about 317.4484327353.

The spelling of 31990392 in words is "thirty-one million, nine hundred ninety thousand, three hundred ninety-two".