31990608 has 120 divisors (see below), whose sum is σ = 100743552. Its totient is φ = 9402624.

The previous prime is 31990601. The next prime is 31990649. The reversal of 31990608 is 80609913.

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 (31990601) 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, 42685 + ... + 43427.

Almost surely, 2^31990608 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 31990608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50371776).

31990608 is an abundant number, since it is smaller than the sum of its proper divisors (68752944).

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

31990608 is a wasteful number, since it uses less digits than its factorization.

31990608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793 (or 784 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 31990608 is about 5656.0240452106. The cubic root of 31990608 is about 317.4491472072.

The spelling of 31990608 in words is "thirty-one million, nine hundred ninety thousand, six hundred eight".