668888866 has 16 divisors (see below), whose sum is σ = 1037038464. Its totient is φ = 323381104.

The previous prime is 668888861. The next prime is 668888867.

It is a happy number.

668888866 is nontrivially palindromic in base 10.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 668888798 and 668888807.

It is not an unprimeable number, because it can be changed into a prime (668888861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35065 + ... + 50668.

It is an arithmetic number, because the mean of its divisors is an integer number (64814904).

Almost surely, 2^668888866 is an apocalyptic number.

668888866 is a deficient number, since it is larger than the sum of its proper divisors (368149598).

668888866 is a wasteful number, since it uses less digits than its factorization.

668888866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85865.

The product of its digits is 42467328, while the sum is 64.

The square root of 668888866 is about 25862.8858791899. The cubic root of 668888866 is about 874.5500232200.

The spelling of 668888866 in words is "six hundred sixty-eight million, eight hundred eighty-eight thousand, eight hundred sixty-six".