31139904 has 56 divisors (see below), whose sum is σ = 83474560. Its totient is φ = 10243584.

The previous prime is 31139893. The next prime is 31139929. The reversal of 31139904 is 40993113.

It is a super-2 number, since 2×31139904² = 1939387242258432, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14142 + ... + 16194.

Almost surely, 2^31139904 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 31139904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41737280).

31139904 is an abundant number, since it is smaller than the sum of its proper divisors (52334656).

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

31139904 is a wasteful number, since it uses less digits than its factorization.

31139904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2147 (or 2137 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 31139904 is about 5580.3139696616. The cubic root of 31139904 is about 314.6099278464.

The spelling of 31139904 in words is "thirty-one million, one hundred thirty-nine thousand, nine hundred four".