666918278785 has 8 divisors (see below), whose sum is σ = 873056655936. Its totient is φ = 485031475440.

The previous prime is 666918278777. The next prime is 666918278801. The reversal of 666918278785 is 587872819666.

666918278785 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 666918278785 - 2³ = 666918278777 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6062893389 + ... + 6062893498.

It is an arithmetic number, because the mean of its divisors is an integer number (109132081992).

Almost surely, 2^666918278785 is an apocalyptic number.

It is an amenable number.

666918278785 is a deficient number, since it is larger than the sum of its proper divisors (206138377151).

666918278785 is a wasteful number, since it uses less digits than its factorization.

666918278785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12125786903.

The product of its digits is 487710720, while the sum is 73.

The spelling of 666918278785 in words is "six hundred sixty-six billion, nine hundred eighteen million, two hundred seventy-eight thousand, seven hundred eighty-five".