640020648 has 32 divisors (see below), whose sum is σ = 1600976160. Its totient is φ = 213216960.

The previous prime is 640020611. The next prime is 640020659. The reversal of 640020648 is 846020046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40978 + ... + 54398.

It is an arithmetic number, because the mean of its divisors is an integer number (50030505).

Almost surely, 2^640020648 is an apocalyptic number.

It is an amenable number.

640020648 is an abundant number, since it is smaller than the sum of its proper divisors (960955512).

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

640020648 is a wasteful number, since it uses less digits than its factorization.

640020648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15417 (or 15413 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 640020648 is about 25298.6293699876. The cubic root of 640020648 is about 861.7831435730.

The spelling of 640020648 in words is "six hundred forty million, twenty thousand, six hundred forty-eight".