640453912 has 24 divisors (see below), whose sum is σ = 1396909260. Its totient is φ = 274480080.

The previous prime is 640453873. The next prime is 640453939. The reversal of 640453912 is 219354046.

It is a happy number.

It is a super-2 number, since 2×640453912² = 820362426792207488, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 816514 + ... + 817297.

Almost surely, 2^640453912 is an apocalyptic number.

It is an amenable number.

640453912 is an abundant number, since it is smaller than the sum of its proper divisors (756455348).

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

640453912 is a wasteful number, since it uses less digits than its factorization.

640453912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1633831 (or 1633820 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 640453912 is about 25307.1909148368. The cubic root of 640453912 is about 861.9775619829.

The spelling of 640453912 in words is "six hundred forty million, four hundred fifty-three thousand, nine hundred twelve".