645968832 has 28 divisors (see below), whose sum is σ = 1709126376. Its totient is φ = 215322880.

The previous prime is 645968819. The next prime is 645968849. The reversal of 645968832 is 238869546.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1682019 + ... + 1682402.

Almost surely, 2^645968832 is an apocalyptic number.

It is an amenable number.

645968832 is an abundant number, since it is smaller than the sum of its proper divisors (1063157544).

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

645968832 is a wasteful number, since it uses less digits than its factorization.

645968832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3364436 (or 3364426 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 51.

The square root of 645968832 is about 25415.9169026026. The cubic root of 645968832 is about 864.4446442453. Note that the first 3 decimals are identical.

The spelling of 645968832 in words is "six hundred forty-five million, nine hundred sixty-eight thousand, eight hundred thirty-two".