640392496 has 20 divisors (see below), whose sum is σ = 1294707312. Its totient is φ = 306274496.

The previous prime is 640392461. The next prime is 640392497. The reversal of 640392496 is 694293046.

It is a super-2 number, since 2×640392496² = 820205097866220032, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640392497) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 869731 + ... + 870466.

Almost surely, 2^640392496 is an apocalyptic number.

It is an amenable number.

640392496 is an abundant number, since it is smaller than the sum of its proper divisors (654314816).

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

640392496 is a wasteful number, since it uses less digits than its factorization.

640392496 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740228 (or 1740222 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 43.

The square root of 640392496 is about 25305.9774756874. The cubic root of 640392496 is about 861.9500081365.

The spelling of 640392496 in words is "six hundred forty million, three hundred ninety-two thousand, four hundred ninety-six".