31997696651 has 2 divisors, whose sum is σ = 31997696652. Its totient is φ = 31997696650.

The previous prime is 31997696639. The next prime is 31997696659. The reversal of 31997696651 is 15669679913.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31997696651 is a prime.

It is not a weakly prime, because it can be changed into another prime (31997696659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15998848325 + 15998848326.

It is an arithmetic number, because the mean of its divisors is an integer number (15998848326).

Almost surely, 2^31997696651 is an apocalyptic number.

31997696651 is a deficient number, since it is larger than the sum of its proper divisors (1).

31997696651 is an equidigital number, since it uses as much as digits as its factorization.

31997696651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16533720, while the sum is 62.

The spelling of 31997696651 in words is "thirty-one billion, nine hundred ninety-seven million, six hundred ninety-six thousand, six hundred fifty-one".