31980393081 has 64 divisors (see below), whose sum is σ = 61742016000. Its totient is φ = 15876476928.

The previous prime is 31980393061. The next prime is 31980393097. The reversal of 31980393081 is 18039308913.

It is a happy number.

It is not a de Polignac number, because 31980393081 - 2¹⁷ = 31980262009 is a prime.

It is a super-2 number, since 2×31980393081² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31980393031) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 341056 + ... + 424593.

It is an arithmetic number, because the mean of its divisors is an integer number (964719000).

Almost surely, 2^31980393081 is an apocalyptic number.

It is an amenable number.

31980393081 is a deficient number, since it is larger than the sum of its proper divisors (29761622919).

31980393081 is a wasteful number, since it uses less digits than its factorization.

31980393081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765695 (or 765689 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The spelling of 31980393081 in words is "thirty-one billion, nine hundred eighty million, three hundred ninety-three thousand, eighty-one".