631968256 has 40 divisors (see below), whose sum is σ = 1272775680. Its totient is φ = 313463808.

The previous prime is 631968241. The next prime is 631968257. The reversal of 631968256 is 652869136.

It is not an unprimeable number, because it can be changed into a prime (631968257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60165 + ... + 69883.

It is an arithmetic number, because the mean of its divisors is an integer number (31819392).

Almost surely, 2^631968256 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 631968256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (636387840).

631968256 is an abundant number, since it is smaller than the sum of its proper divisors (640807424).

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

631968256 is an equidigital number, since it uses as much as digits as its factorization.

631968256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9864 (or 9848 counting only the distinct ones).

The product of its digits is 466560, while the sum is 46.

The square root of 631968256 is about 25138.9788177643. The cubic root of 631968256 is about 858.1537171859.

The spelling of 631968256 in words is "six hundred thirty-one million, nine hundred sixty-eight thousand, two hundred fifty-six".