31997696641 has 9 divisors (see below), whose sum is σ = 32303774659. Its totient is φ = 31694496736.

The previous prime is 31997696639. The next prime is 31997696651. The reversal of 31997696641 is 14669679913.

The square root of 31997696641 is 178879.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 563825025 + 31433871616 = 23745^2 + 177296^2 .

It is not a de Polignac number, because 31997696641 - 2¹ = 31997696639 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31997696641.

It is not an unprimeable number, because it can be changed into a prime (31997696651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 20212536 + ... + 20214118.

Almost surely, 2^31997696641 is an apocalyptic number.

31997696641 is the 178879-th square number.

31997696641 is the 89440-th centered octagonal number.

It is an amenable number.

31997696641 is a deficient number, since it is larger than the sum of its proper divisors (306078018).

31997696641 is an frugal number, since it uses more digits than its factorization.

31997696641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3392 (or 1696 counting only the distinct ones).

The product of its digits is 13226976, while the sum is 61.

The spelling of 31997696641 in words is "thirty-one billion, nine hundred ninety-seven million, six hundred ninety-six thousand, six hundred forty-one".