645309872 has 10 divisors (see below), whose sum is σ = 1250287908. Its totient is φ = 322654928.

The previous prime is 645309869. The next prime is 645309881. The reversal of 645309872 is 278903546.

645309872 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20165918 + ... + 20165949.

Almost surely, 2^645309872 is an apocalyptic number.

It is an amenable number.

645309872 is a deficient number, since it is larger than the sum of its proper divisors (604978036).

645309872 is a wasteful number, since it uses less digits than its factorization.

645309872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40331875 (or 40331869 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 44.

The square root of 645309872 is about 25402.9500649039. The cubic root of 645309872 is about 864.1506010339.

The spelling of 645309872 in words is "six hundred forty-five million, three hundred nine thousand, eight hundred seventy-two".