813931538 has 24 divisors (see below), whose sum is σ = 1472622912. Its totient is φ = 330466392.

The previous prime is 813931529. The next prime is 813931543. The reversal of 813931538 is 835139318.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 813931495 and 813931504.

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 11 ways as a sum of consecutive naturals, for example, 75470 + ... + 85577.

It is an arithmetic number, because the mean of its divisors is an integer number (61359288).

Almost surely, 2^813931538 is an apocalyptic number.

813931538 is a deficient number, since it is larger than the sum of its proper divisors (658691374).

813931538 is a wasteful number, since it uses less digits than its factorization.

813931538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161094 (or 161075 counting only the distinct ones).

The product of its digits is 77760, while the sum is 41.

The square root of 813931538 is about 28529.4854142166. The cubic root of 813931538 is about 933.6754914153.

The spelling of 813931538 in words is "eight hundred thirteen million, nine hundred thirty-one thousand, five hundred thirty-eight".