645504875 has 16 divisors (see below), whose sum is σ = 852980544. Its totient is φ = 486025600.

The previous prime is 645504869. The next prime is 645504883. The reversal of 645504875 is 578405546.

It is not a de Polignac number, because 645504875 - 2⁸ = 645504619 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149759 + ... + 154008.

It is an arithmetic number, because the mean of its divisors is an integer number (53311284).

Almost surely, 2^645504875 is an apocalyptic number.

645504875 is a deficient number, since it is larger than the sum of its proper divisors (207475669).

645504875 is a wasteful number, since it uses less digits than its factorization.

645504875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303799 (or 303789 counting only the distinct ones).

The product of its (nonzero) digits is 672000, while the sum is 44.

The square root of 645504875 is about 25406.7879709341. The cubic root of 645504875 is about 864.2376367336.

The spelling of 645504875 in words is "six hundred forty-five million, five hundred four thousand, eight hundred seventy-five".