631997856 has 192 divisors, whose sum is σ = 2133734400. Its totient is φ = 178253568.

The previous prime is 631997827. The next prime is 631997857. The reversal of 631997856 is 658799136.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (631997857) 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 31 ways as a sum of consecutive naturals, for example, 501355 + ... + 502613.

It is an arithmetic number, because the mean of its divisors is an integer number (11113200).

Almost surely, 2^631997856 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 631997856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1066867200).

631997856 is an abundant number, since it is smaller than the sum of its proper divisors (1501736544).

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

631997856 is a wasteful number, since it uses less digits than its factorization.

631997856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1368 (or 1354 counting only the distinct ones).

The product of its digits is 2449440, while the sum is 54.

The square root of 631997856 is about 25139.5675380465. The cubic root of 631997856 is about 858.1671149862.

The spelling of 631997856 in words is "six hundred thirty-one million, nine hundred ninety-seven thousand, eight hundred fifty-six".