645724064 has 24 divisors (see below), whose sum is σ = 1286591040. Its totient is φ = 318970816.

The previous prime is 645724049. The next prime is 645724097. The reversal of 645724064 is 460427546.

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, 118904 + ... + 124215.

It is an arithmetic number, because the mean of its divisors is an integer number (53607960).

Almost surely, 2^645724064 is an apocalyptic number.

It is an amenable number.

645724064 is a deficient number, since it is larger than the sum of its proper divisors (640866976).

645724064 is a wasteful number, since it uses less digits than its factorization.

645724064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243212 (or 243204 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 38.

The square root of 645724064 is about 25411.1011961308. The cubic root of 645724064 is about 864.3354464499.

The spelling of 645724064 in words is "six hundred forty-five million, seven hundred twenty-four thousand, sixty-four".