666936888639666 has 8 divisors (see below), whose sum is σ = 1333873777279344. Its totient is φ = 222312296213220.

The previous prime is 666936888639547. The next prime is 666936888639667.

666936888639666 is nontrivially palindromic in base 10.

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

666936888639666 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (666936888639667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55578074053300 + ... + 55578074053311.

It is an arithmetic number, because the mean of its divisors is an integer number (166734222159918).

Almost surely, 2^{666936888639666} is an apocalyptic number.

666936888639666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

666936888639666 is a wasteful number, since it uses less digits than its factorization.

666936888639666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111156148106616.

The product of its digits is 626913312768, while the sum is 96.

The spelling of 666936888639666 in words is "six hundred sixty-six trillion, nine hundred thirty-six billion, eight hundred eighty-eight million, six hundred thirty-nine thousand, six hundred sixty-six".