631688256 has 84 divisors (see below), whose sum is σ = 1818906700. Its totient is φ = 209599488.

The previous prime is 631688249. The next prime is 631688273. The reversal of 631688256 is 652886136.

631688256 is a `hidden beast` number, since 6 + 316 + 88 + 256 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 316270656 + 315417600 = 17784^2 + 17760^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 129510 + ... + 134298.

Almost surely, 2^631688256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 631688256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (909453350).

631688256 is an abundant number, since it is smaller than the sum of its proper divisors (1187218444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

631688256 is a wasteful number, since it uses less digits than its factorization.

631688256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5036 (or 5023 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 631688256 is about 25133.4091599210. The cubic root of 631688256 is about 858.0269605364.

The spelling of 631688256 in words is "six hundred thirty-one million, six hundred eighty-eight thousand, two hundred fifty-six".