31520994688 has 32 divisors (see below), whose sum is σ = 63121147560. Its totient is φ = 15678824448.

The previous prime is 31520994683. The next prime is 31520994689. The reversal of 31520994688 is 88649902513.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×31520994688² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31520994683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 613270 + ... + 662677.

Almost surely, 2^31520994688 is an apocalyptic number.

It is an amenable number.

31520994688 is an abundant number, since it is smaller than the sum of its proper divisors (31600152872).

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

31520994688 is a wasteful number, since it uses less digits than its factorization.

31520994688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1276154 (or 1276142 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 55.

The spelling of 31520994688 in words is "thirty-one billion, five hundred twenty million, nine hundred ninety-four thousand, six hundred eighty-eight".