645873824 has 12 divisors (see below), whose sum is σ = 1271564154. Its totient is φ = 322936896.

The previous prime is 645873817. The next prime is 645873829. The reversal of 645873824 is 428378546.

It can be written as a sum of positive squares in only one way, i.e., 548496400 + 97377424 = 23420^2 + 9868^2 .

It is not an unprimeable number, because it can be changed into a prime (645873829) 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 as a sum of consecutive naturals, namely, 10091747 + ... + 10091810.

Almost surely, 2^645873824 is an apocalyptic number.

It is an amenable number.

645873824 is a deficient number, since it is larger than the sum of its proper divisors (625690330).

645873824 is a wasteful number, since it uses less digits than its factorization.

645873824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20183567 (or 20183559 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 47.

The square root of 645873824 is about 25414.0477689014. The cubic root of 645873824 is about 864.4022618168.

The spelling of 645873824 in words is "six hundred forty-five million, eight hundred seventy-three thousand, eight hundred twenty-four".