668665566866 has 32 divisors (see below), whose sum is σ = 1095296924736. Its totient is φ = 303628840000.

The previous prime is 668665566859. The next prime is 668665566929.

668665566866 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×668665566866² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 668665566793 and 668665566802.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 150225941 + ... + 150230391.

It is an arithmetic number, because the mean of its divisors is an integer number (34228028898).

Almost surely, 2^668665566866 is an apocalyptic number.

668665566866 is a deficient number, since it is larger than the sum of its proper divisors (426631357870).

668665566866 is a wasteful number, since it uses less digits than its factorization.

668665566866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9898.

The product of its digits is 2687385600, while the sum is 74.

The spelling of 668665566866 in words is "six hundred sixty-eight billion, six hundred sixty-five million, five hundred sixty-six thousand, eight hundred sixty-six".