631090640 has 40 divisors (see below), whose sum is σ = 1468332360. Its totient is φ = 252256256.

The previous prime is 631090627. The next prime is 631090651. The reversal of 631090640 is 46090136.

It can be written as a sum of positive squares in 4 ways, for example, as 1281424 + 629809216 = 1132^2 + 25096^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211076 + ... + 214044.

It is an arithmetic number, because the mean of its divisors is an integer number (36708309).

Almost surely, 2^631090640 is an apocalyptic number.

It is an amenable number.

631090640 is an abundant number, since it is smaller than the sum of its proper divisors (837241720).

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

631090640 is a wasteful number, since it uses less digits than its factorization.

631090640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5639 (or 5633 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 631090640 is about 25121.5174700893. The cubic root of 631090640 is about 857.7562930437.

The spelling of 631090640 in words is "six hundred thirty-one million, ninety thousand, six hundred forty".