631651640 has 32 divisors (see below), whose sum is σ = 1445310000. Its totient is φ = 248377344.

The previous prime is 631651627. The next prime is 631651649. The reversal of 631651640 is 46156136.

631651640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 631651597 and 631651606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631651649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131465 + ... + 136184.

Almost surely, 2^631651640 is an apocalyptic number.

It is an amenable number.

631651640 is an abundant number, since it is smaller than the sum of its proper divisors (813658360).

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

631651640 is a wasteful number, since it uses less digits than its factorization.

631651640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267719 (or 267715 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 631651640 is about 25132.6807165491. The cubic root of 631651640 is about 858.0103816190.

The spelling of 631651640 in words is "six hundred thirty-one million, six hundred fifty-one thousand, six hundred forty".