631690917 has 32 divisors (see below), whose sum is σ = 992261760. Its totient is φ = 352408320.

The previous prime is 631690909. The next prime is 631690919. The reversal of 631690917 is 719096136.

It is not a de Polignac number, because 631690917 - 2³ = 631690909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631690919) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 168459 + ... + 172167.

It is an arithmetic number, because the mean of its divisors is an integer number (31008180).

Almost surely, 2^631690917 is an apocalyptic number.

It is an amenable number.

631690917 is a deficient number, since it is larger than the sum of its proper divisors (360570843).

631690917 is a wasteful number, since it uses less digits than its factorization.

631690917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4133.

The product of its (nonzero) digits is 61236, while the sum is 42.

The square root of 631690917 is about 25133.4620973713. The cubic root of 631690917 is about 858.0281653536.

The spelling of 631690917 in words is "six hundred thirty-one million, six hundred ninety thousand, nine hundred seventeen".