666808206668 has 12 divisors (see below), whose sum is σ = 1228330907160. Its totient is φ = 315856518912.

The previous prime is 666808206643. The next prime is 666808206751. The reversal of 666808206668 is 866602808666.

It is a self number, because there is not a number n which added to its sum of digits gives 666808206668.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4386896021 + ... + 4386896172.

It is an arithmetic number, because the mean of its divisors is an integer number (102360908930).

Almost surely, 2^666808206668 is an apocalyptic number.

It is an amenable number.

666808206668 is a deficient number, since it is larger than the sum of its proper divisors (561522700492).

666808206668 is a wasteful number, since it uses less digits than its factorization.

666808206668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8773792216 (or 8773792214 counting only the distinct ones).

The product of its (nonzero) digits is 47775744, while the sum is 62.

The spelling of 666808206668 in words is "six hundred sixty-six billion, eight hundred eight million, two hundred six thousand, six hundred sixty-eight".