631881320 has 64 divisors (see below), whose sum is σ = 1630903680. Its totient is φ = 215836416.

The previous prime is 631881311. The next prime is 631881343. The reversal of 631881320 is 23188136.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73487 + ... + 81633.

It is an arithmetic number, because the mean of its divisors is an integer number (25482870).

Almost surely, 2^631881320 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 631881320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (815451840).

631881320 is an abundant number, since it is smaller than the sum of its proper divisors (999022360).

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

631881320 is a wasteful number, since it uses less digits than its factorization.

631881320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8442 (or 8438 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 631881320 is about 25137.2496506678. The cubic root of 631881320 is about 858.1143650655.

The spelling of 631881320 in words is "six hundred thirty-one million, eight hundred eighty-one thousand, three hundred twenty".