631808 has 22 divisors (see below), whose sum is σ = 1265046. Its totient is φ = 315392.

The previous prime is 631789. The next prime is 631817. The reversal of 631808 is 808136.

It can be written as a sum of positive squares in only one way, i.e., 369664 + 262144 = 608^2 + 512^2 .

It is an unprimeable number.

631808 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 716 + ... + 1332.

2⁶³¹⁸⁰⁸ 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 631808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (632523).

631808 is an abundant number, since it is smaller than the sum of its proper divisors (633238).

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

631808 is an equidigital number, since it uses as much as digits as its factorization.

631808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637 (or 619 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 631808 is about 794.8635102960. The cubic root of 631808 is about 85.8081173506.

The spelling of 631808 in words is "six hundred thirty-one thousand, eight hundred eight".