668688868808 has 8 divisors (see below), whose sum is σ = 1253791629030. Its totient is φ = 334344434400.

The previous prime is 668688868787. The next prime is 668688868823. The reversal of 668688868808 is 808868886866.

It can be written as a sum of positive squares in only one way, i.e., 524259987364 + 144428881444 = 724058^2 + 380038^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41793054293 + ... + 41793054308.

Almost surely, 2^668688868808 is an apocalyptic number.

It is an amenable number.

668688868808 is a deficient number, since it is larger than the sum of its proper divisors (585102760222).

668688868808 is a wasteful number, since it uses less digits than its factorization.

668688868808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83586108607 (or 83586108603 counting only the distinct ones).

The product of its (nonzero) digits is 2717908992, while the sum is 80.

The spelling of 668688868808 in words is "six hundred sixty-eight billion, six hundred eighty-eight million, eight hundred sixty-eight thousand, eight hundred eight".