31390992 has 60 divisors (see below), whose sum is σ = 90892620. Its totient is φ = 10101504.

The previous prime is 31390987. The next prime is 31391033. The reversal of 31390992 is 29909313.

It can be written as a sum of positive squares in 2 ways, for example, as 23970816 + 7420176 = 4896^2 + 2724^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 418 + ... + 7934.

It is an arithmetic number, because the mean of its divisors is an integer number (1514877).

Almost surely, 2^31390992 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31390992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45446310).

31390992 is an abundant number, since it is smaller than the sum of its proper divisors (59501628).

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

31390992 is a wasteful number, since it uses less digits than its factorization.

31390992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7560 (or 7551 counting only the distinct ones).

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

The square root of 31390992 is about 5602.7664595269. The cubic root of 31390992 is about 315.4532552809.

The spelling of 31390992 in words is "thirty-one million, three hundred ninety thousand, nine hundred ninety-two".