664775721784 has 16 divisors (see below), whose sum is σ = 1246475826720. Its totient is φ = 332382168000.

The previous prime is 664775721749. The next prime is 664775721811. The reversal of 664775721784 is 487127577466.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 193104 + ... + 1169119.

It is an arithmetic number, because the mean of its divisors is an integer number (77904739170).

Almost surely, 2^664775721784 is an apocalyptic number.

It is an amenable number.

664775721784 is a deficient number, since it is larger than the sum of its proper divisors (581700104936).

664775721784 is a wasteful number, since it uses less digits than its factorization.

664775721784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1423230 (or 1423226 counting only the distinct ones).

The product of its digits is 110638080, while the sum is 64.

The spelling of 664775721784 in words is "six hundred sixty-four billion, seven hundred seventy-five million, seven hundred twenty-one thousand, seven hundred eighty-four".