666508866 has 64 divisors (see below), whose sum is σ = 1459200000. Its totient is φ = 202176000.

The previous prime is 666508823. The next prime is 666508889. The reversal of 666508866 is 668805666.

666508866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 533010 + ... + 534258.

It is an arithmetic number, because the mean of its divisors is an integer number (22800000).

Almost surely, 2^666508866 is an apocalyptic number.

666508866 is an abundant number, since it is smaller than the sum of its proper divisors (792691134).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666508866 is a wasteful number, since it uses less digits than its factorization.

666508866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1455.

The product of its (nonzero) digits is 2488320, while the sum is 51.

The square root of 666508866 is about 25816.8329970971. The cubic root of 666508866 is about 873.5115335075.

The spelling of 666508866 in words is "six hundred sixty-six million, five hundred eight thousand, eight hundred sixty-six".