640704500 has 48 divisors (see below), whose sum is σ = 1481629968. Its totient is φ = 241203200.

The previous prime is 640704481. The next prime is 640704553. The reversal of 640704500 is 5407046.

It can be written as a sum of positive squares in 8 ways, for example, as 32194276 + 608510224 = 5674^2 + 24668^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 640704500.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29189 + ... + 46188.

It is an arithmetic number, because the mean of its divisors is an integer number (30867291).

Almost surely, 2^640704500 is an apocalyptic number.

It is an amenable number.

640704500 is an abundant number, since it is smaller than the sum of its proper divisors (840925468).

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

640704500 is a wasteful number, since it uses less digits than its factorization.

640704500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75413 (or 75401 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 640704500 is about 25312.1413554839. The cubic root of 640704500 is about 862.0899682331.

The spelling of 640704500 in words is "six hundred forty million, seven hundred four thousand, five hundred".