640608136 has 16 divisors (see below), whose sum is σ = 1372731840. Its totient is φ = 274546320.

The previous prime is 640608131. The next prime is 640608179. The reversal of 640608136 is 631806046.

640608136 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (640608131) 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, 5719660 + ... + 5719771.

It is an arithmetic number, because the mean of its divisors is an integer number (85795740).

Almost surely, 2^640608136 is an apocalyptic number.

It is an amenable number.

640608136 is an abundant number, since it is smaller than the sum of its proper divisors (732123704).

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

640608136 is a wasteful number, since it uses less digits than its factorization.

640608136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11439444 (or 11439440 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 640608136 is about 25310.2377705149. The cubic root of 640608136 is about 862.0467457060.

The spelling of 640608136 in words is "six hundred forty million, six hundred eight thousand, one hundred thirty-six".