640463256 has 48 divisors (see below), whose sum is σ = 1735844760. Its totient is φ = 213333120.

The previous prime is 640463249. The next prime is 640463261. The reversal of 640463256 is 652364046.

640463256 is a `hidden beast` number, since 640 + 4 + 6 + 3 + 2 + 5 + 6 = 666.

It is a super-2 number, since 2×640463256² = 820386364572243072, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 640463256.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 141996 + ... + 146436.

Almost surely, 2^640463256 is an apocalyptic number.

It is an amenable number.

640463256 is an abundant number, since it is smaller than the sum of its proper divisors (1095381504).

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

640463256 is a wasteful number, since it uses less digits than its factorization.

640463256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6456 (or 6449 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 640463256 is about 25307.3755257237. The cubic root of 640463256 is about 861.9817539469.

The spelling of 640463256 in words is "six hundred forty million, four hundred sixty-three thousand, two hundred fifty-six".