645899504 has 20 divisors (see below), whose sum is σ = 1259833800. Its totient is φ = 320781120.

The previous prime is 645899461. The next prime is 645899519. The reversal of 645899504 is 405998546.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133082 + ... + 137849.

It is an arithmetic number, because the mean of its divisors is an integer number (62991690).

Almost surely, 2^645899504 is an apocalyptic number.

It is an amenable number.

645899504 is a deficient number, since it is larger than the sum of its proper divisors (613934296).

645899504 is a wasteful number, since it uses less digits than its factorization.

645899504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271088 (or 271082 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 50.

The square root of 645899504 is about 25414.5529962657. The cubic root of 645899504 is about 864.4137179016.

The spelling of 645899504 in words is "six hundred forty-five million, eight hundred ninety-nine thousand, five hundred four".