640465028 has 12 divisors (see below), whose sum is σ = 1280930112. Its totient is φ = 274485000.

The previous prime is 640465019. The next prime is 640465031. The reversal of 640465028 is 820564046.

640465028 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11436848 + ... + 11436903.

It is an arithmetic number, because the mean of its divisors is an integer number (106744176).

Almost surely, 2^640465028 is an apocalyptic number.

It is an amenable number.

640465028 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

640465028 is a wasteful number, since it uses less digits than its factorization.

640465028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22873762 (or 22873760 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 35.

The square root of 640465028 is about 25307.4105352563. The cubic root of 640465028 is about 861.9825489080.

The spelling of 640465028 in words is "six hundred forty million, four hundred sixty-five thousand, twenty-eight".