640418688 has 384 divisors, whose sum is σ = 2339064000. Its totient is φ = 163676160.

The previous prime is 640418659. The next prime is 640418717. The reversal of 640418688 is 886814046.

It is an interprime number because it is at equal distance from previous prime (640418659) and next prime (640418717).

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4298038 + ... + 4298186.

Almost surely, 2^640418688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640418688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1169532000).

640418688 is an abundant number, since it is smaller than the sum of its proper divisors (1698645312).

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

640418688 is a wasteful number, since it uses less digits than its factorization.

640418688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 45.

The square root of 640418688 is about 25306.4949765865. The cubic root of 640418688 is about 861.9617592042.

The spelling of 640418688 in words is "six hundred forty million, four hundred eighteen thousand, six hundred eighty-eight".