640468885 has 8 divisors (see below), whose sum is σ = 878357376. Its totient is φ = 439178640.

The previous prime is 640468877. The next prime is 640468889. The reversal of 640468885 is 588864046.

640468885 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 640468885 - 2³ = 640468877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640468889) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9149521 + ... + 9149590.

It is an arithmetic number, because the mean of its divisors is an integer number (109794672).

Almost surely, 2^640468885 is an apocalyptic number.

It is an amenable number.

640468885 is a deficient number, since it is larger than the sum of its proper divisors (237888491).

640468885 is a wasteful number, since it uses less digits than its factorization.

640468885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18299123.

The product of its (nonzero) digits is 1474560, while the sum is 49.

The square root of 640468885 is about 25307.4867381176. The cubic root of 640468885 is about 861.9842792445.

The spelling of 640468885 in words is "six hundred forty million, four hundred sixty-eight thousand, eight hundred eighty-five".