640608642220 has 48 divisors (see below), whose sum is σ = 1414481342400. Its totient is φ = 243351601920.

The previous prime is 640608642187. The next prime is 640608642221. The reversal of 640608642220 is 22246806046.

It is not an unprimeable number, because it can be changed into a prime (640608642221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9017880 + ... + 9088639.

It is an arithmetic number, because the mean of its divisors is an integer number (29468361300).

Almost surely, 2^640608642220 is an apocalyptic number.

It is an amenable number.

640608642220 is an abundant number, since it is smaller than the sum of its proper divisors (773872700180).

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

640608642220 is a wasteful number, since it uses less digits than its factorization.

640608642220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18106618 (or 18106616 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 40.

The spelling of 640608642220 in words is "six hundred forty billion, six hundred eight million, six hundred forty-two thousand, two hundred twenty".