645403504 has 20 divisors (see below), whose sum is σ = 1324026864. Its totient is φ = 303719168.

The previous prime is 645403501. The next prime is 645403511. The reversal of 645403504 is 405304546.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645403501) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1186132 + ... + 1186675.

Almost surely, 2^645403504 is an apocalyptic number.

It is an amenable number.

645403504 is an abundant number, since it is smaller than the sum of its proper divisors (678623360).

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

645403504 is a wasteful number, since it uses less digits than its factorization.

645403504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2372832 (or 2372826 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 31.

The square root of 645403504 is about 25404.7929336179. The cubic root of 645403504 is about 864.1923939976.

The spelling of 645403504 in words is "six hundred forty-five million, four hundred three thousand, five hundred four".