631966401 has 64 divisors (see below), whose sum is σ = 1059379200. Its totient is φ = 368971200.

The previous prime is 631966397. The next prime is 631966421. The reversal of 631966401 is 104669136.

631966401 is a `hidden beast` number, since 6 + 3 + 1 + 9 + 6 + 640 + 1 = 666.

It is not a de Polignac number, because 631966401 - 2² = 631966397 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (631966421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1439340 + ... + 1439778.

It is an arithmetic number, because the mean of its divisors is an integer number (16552800).

Almost surely, 2^631966401 is an apocalyptic number.

It is an amenable number.

631966401 is a deficient number, since it is larger than the sum of its proper divisors (427412799).

631966401 is a wasteful number, since it uses less digits than its factorization.

631966401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627 (or 621 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 631966401 is about 25138.9419228415. The cubic root of 631966401 is about 858.1528775463.

The spelling of 631966401 in words is "six hundred thirty-one million, nine hundred sixty-six thousand, four hundred one".