647565664 has 12 divisors (see below), whose sum is σ = 1274894964. Its totient is φ = 323782816.

The previous prime is 647565647. The next prime is 647565697. The reversal of 647565664 is 466565746.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10118182 + ... + 10118245.

It is an arithmetic number, because the mean of its divisors is an integer number (106241247).

Almost surely, 2^647565664 is an apocalyptic number.

It is an amenable number.

647565664 is a deficient number, since it is larger than the sum of its proper divisors (627329300).

647565664 is a wasteful number, since it uses less digits than its factorization.

647565664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20236437 (or 20236429 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 49.

The square root of 647565664 is about 25447.3115279394. The cubic root of 647565664 is about 865.1563591848.

The spelling of 647565664 in words is "six hundred forty-seven million, five hundred sixty-five thousand, six hundred sixty-four".