640552208 has 20 divisors (see below), whose sum is σ = 1295030208. Its totient is φ = 306350880.

The previous prime is 640552181. The next prime is 640552219. The reversal of 640552208 is 802255046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 869948 + ... + 870683.

Almost surely, 2^640552208 is an apocalyptic number.

It is an amenable number.

640552208 is an abundant number, since it is smaller than the sum of its proper divisors (654478000).

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

640552208 is a wasteful number, since it uses less digits than its factorization.

640552208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1740662 (or 1740656 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 32.

The square root of 640552208 is about 25309.1328970394. The cubic root of 640552208 is about 862.0216581104.

The spelling of 640552208 in words is "six hundred forty million, five hundred fifty-two thousand, two hundred eight".