631991967625 has 8 divisors (see below), whose sum is σ = 788725975752. Its totient is φ = 505593574000.

The previous prime is 631991967613. The next prime is 631991967643. The reversal of 631991967625 is 526769199136.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 234059401 + 631757908224 = 15299^2 + 794832^2 .

It is not a de Polignac number, because 631991967625 - 2²⁵ = 631958413193 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2527967746 + ... + 2527967995.

It is an arithmetic number, because the mean of its divisors is an integer number (98590746969).

Almost surely, 2^631991967625 is an apocalyptic number.

It is an amenable number.

631991967625 is a deficient number, since it is larger than the sum of its proper divisors (156734008127).

631991967625 is an equidigital number, since it uses as much as digits as its factorization.

631991967625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5055935756 (or 5055935746 counting only the distinct ones).

The product of its digits is 33067440, while the sum is 64.

The spelling of 631991967625 in words is "six hundred thirty-one billion, nine hundred ninety-one million, nine hundred sixty-seven thousand, six hundred twenty-five".