640442016 has 36 divisors (see below), whose sum is σ = 1821257802. Its totient is φ = 213480576.

The previous prime is 640442009. The next prime is 640442029. The reversal of 640442016 is 610244046.

640442016 is a `hidden beast` number, since 640 + 4 + 4 + 2 + 0 + 16 = 666.

It can be written as a sum of positive squares in only one way, i.e., 331385616 + 309056400 = 18204^2 + 17580^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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 5 ways as a sum of consecutive naturals, for example, 1111591 + ... + 1112166.

Almost surely, 2^640442016 is an apocalyptic number.

It is an amenable number.

640442016 is an abundant number, since it is smaller than the sum of its proper divisors (1180815786).

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

640442016 is a wasteful number, since it uses less digits than its factorization.

640442016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2223773 (or 2223762 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 640442016 is about 25306.9558817334. The cubic root of 640442016 is about 861.9722250657.

The spelling of 640442016 in words is "six hundred forty million, four hundred forty-two thousand, sixteen".