31138836 has 24 divisors (see below), whose sum is σ = 72873024. Its totient is φ = 10348800.

The previous prime is 31138829. The next prime is 31138841. The reversal of 31138836 is 63883113.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 31138797 and 31138806.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 561 + ... + 7911.

It is an arithmetic number, because the mean of its divisors is an integer number (3036376).

Almost surely, 2^31138836 is an apocalyptic number.

It is an amenable number.

31138836 is an abundant number, since it is smaller than the sum of its proper divisors (41734188).

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

31138836 is a wasteful number, since it uses less digits than its factorization.

31138836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7711 (or 7709 counting only the distinct ones).

The product of its digits is 10368, while the sum is 33.

The square root of 31138836 is about 5580.2182753007. The cubic root of 31138836 is about 314.6063310975.

The spelling of 31138836 in words is "thirty-one million, one hundred thirty-eight thousand, eight hundred thirty-six".