31351720768 has 28 divisors (see below), whose sum is σ = 62240443972. Its totient is φ = 15669089280.

The previous prime is 31351720747. The next prime is 31351720801. The reversal of 31351720768 is 86702715313.

It can be written as a sum of positive squares in 2 ways, for example, as 13982589504 + 17369131264 = 118248^2 + 131792^2 .

It is a super-2 number, since 2×31351720768² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45196 + ... + 254452.

It is an arithmetic number, because the mean of its divisors is an integer number (2222872999).

Almost surely, 2^31351720768 is an apocalyptic number.

It is an amenable number.

31351720768 is a deficient number, since it is larger than the sum of its proper divisors (30888723204).

31351720768 is a wasteful number, since it uses less digits than its factorization.

31351720768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211610 (or 211600 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 43.

The spelling of 31351720768 in words is "thirty-one billion, three hundred fifty-one million, seven hundred twenty thousand, seven hundred sixty-eight".