668666866 has 8 divisors (see below), whose sum is σ = 1146286080. Its totient is φ = 286571508.

The previous prime is 668666857. The next prime is 668666927.

668666866 is nontrivially palindromic in base 10 and base 13.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 668666866.

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, 23880946 + ... + 23880973.

It is an arithmetic number, because the mean of its divisors is an integer number (143285760).

Almost surely, 2^668666866 is an apocalyptic number.

668666866 is a deficient number, since it is larger than the sum of its proper divisors (477619214).

668666866 is a wasteful number, since it uses less digits than its factorization.

668666866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47761928.

The product of its digits is 17915904, while the sum is 58.

The square root of 668666866 is about 25858.5936585886. The cubic root of 668666866 is about 874.4532599668.

The spelling of 668666866 in words is "six hundred sixty-eight million, six hundred sixty-six thousand, eight hundred sixty-six".