668565753872 has 10 divisors (see below), whose sum is σ = 1295346148158. Its totient is φ = 334282876928.

The previous prime is 668565753871. The next prime is 668565753887. The reversal of 668565753872 is 278357565866.

It can be written as a sum of positive squares in only one way, i.e., 499730231056 + 168835522816 = 706916^2 + 410896^2 .

It is not an unprimeable number, because it can be changed into a prime (668565753871) by changing a digit.

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 as a sum of consecutive naturals, namely, 20892679793 + ... + 20892679824.

Almost surely, 2^668565753872 is an apocalyptic number.

It is an amenable number.

668565753872 is a deficient number, since it is larger than the sum of its proper divisors (626780394286).

668565753872 is a wasteful number, since it uses less digits than its factorization.

668565753872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41785359625 (or 41785359619 counting only the distinct ones).

The product of its digits is 508032000, while the sum is 68.

The spelling of 668565753872 in words is "six hundred sixty-eight billion, five hundred sixty-five million, seven hundred fifty-three thousand, eight hundred seventy-two".