645744333664 has 24 divisors (see below), whose sum is σ = 1272876790248. Its totient is φ = 322474037760.

The previous prime is 645744333601. The next prime is 645744333673. The reversal of 645744333664 is 466333447546.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12415177 + ... + 12467080.

It is an arithmetic number, because the mean of its divisors is an integer number (53036532927).

Almost surely, 2^645744333664 is an apocalyptic number.

It is an amenable number.

645744333664 is a deficient number, since it is larger than the sum of its proper divisors (627132456584).

645744333664 is a wasteful number, since it uses less digits than its factorization.

645744333664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24883078 (or 24883070 counting only the distinct ones).

The product of its digits is 52254720, while the sum is 55.

The spelling of 645744333664 in words is "six hundred forty-five billion, seven hundred forty-four million, three hundred thirty-three thousand, six hundred sixty-four".