666887788666 has 8 divisors (see below), whose sum is σ = 1091270926944. Its totient is φ = 303130813020.

The previous prime is 666887788649. The next prime is 666887788691.

666887788666 is nontrivially palindromic in base 10.

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

It is a zygodrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 666887788666.

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, 15156540630 + ... + 15156540673.

It is an arithmetic number, because the mean of its divisors is an integer number (136408865868).

Almost surely, 2^666887788666 is an apocalyptic number.

666887788666 is a deficient number, since it is larger than the sum of its proper divisors (424383138278).

666887788666 is a wasteful number, since it uses less digits than its factorization.

666887788666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30313081316.

The product of its digits is 9364045824, while the sum is 82.

The spelling of 666887788666 in words is "six hundred sixty-six billion, eight hundred eighty-seven million, seven hundred eighty-eight thousand, six hundred sixty-six".