631881881937 has 12 divisors (see below), whose sum is σ = 937386335860. Its totient is φ = 409869328608.

The previous prime is 631881881921. The next prime is 631881881951. The reversal of 631881881937 is 739188188136.

It can be written as a sum of positive squares in 2 ways, for example, as 286095544641 + 345786337296 = 534879^2 + 588036^2 .

It is not a de Polignac number, because 631881881937 - 2⁴ = 631881881921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631881881237) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 948771262 + ... + 948771927.

Almost surely, 2^631881881937 is an apocalyptic number.

It is an amenable number.

631881881937 is a deficient number, since it is larger than the sum of its proper divisors (305504453923).

631881881937 is a wasteful number, since it uses less digits than its factorization.

631881881937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1897543232 (or 1897543229 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 63.

The spelling of 631881881937 in words is "six hundred thirty-one billion, eight hundred eighty-one million, eight hundred eighty-one thousand, nine hundred thirty-seven".