31557996738 has 20 divisors (see below), whose sum is σ = 70713289350. Its totient is φ = 10519332192.

The previous prime is 31557996731. The next prime is 31557996739. The reversal of 31557996738 is 83769975513.

31557996738 is a `hidden beast` number, since 3 + 1 + 557 + 9 + 9 + 6 + 73 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19958060529 + 11599936209 = 141273^2 + 107703^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31557996731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 97401063 + ... + 97401386.

Almost surely, 2^31557996738 is an apocalyptic number.

31557996738 is an abundant number, since it is smaller than the sum of its proper divisors (39155292612).

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

31557996738 is a wasteful number, since it uses less digits than its factorization.

31557996738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194802463 (or 194802454 counting only the distinct ones).

The product of its digits is 42865200, while the sum is 63.

The spelling of 31557996738 in words is "thirty-one billion, five hundred fifty-seven million, nine hundred ninety-six thousand, seven hundred thirty-eight".