631609931 has 2 divisors, whose sum is σ = 631609932. Its totient is φ = 631609930.

The previous prime is 631609919. The next prime is 631609973. The reversal of 631609931 is 139906136.

631609931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 631609931 - 2²² = 627415627 is a prime.

It is a super-2 number, since 2×631609931² = 797862209875649522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (631609331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315804965 + 315804966.

It is an arithmetic number, because the mean of its divisors is an integer number (315804966).

Almost surely, 2^631609931 is an apocalyptic number.

631609931 is a deficient number, since it is larger than the sum of its proper divisors (1).

631609931 is an equidigital number, since it uses as much as digits as its factorization.

631609931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26244, while the sum is 38.

The square root of 631609931 is about 25131.8509266628. The cubic root of 631609931 is about 857.9914959229.

The spelling of 631609931 in words is "six hundred thirty-one million, six hundred nine thousand, nine hundred thirty-one".