666984739679 has 4 divisors (see below), whose sum is σ = 666989836800. Its totient is φ = 666979642560.

The previous prime is 666984739651. The next prime is 666984739703. The reversal of 666984739679 is 976937489666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 666984739679 - 2¹² = 666984735583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666984739879) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2346962 + ... + 2615759.

It is an arithmetic number, because the mean of its divisors is an integer number (166747459200).

Almost surely, 2^666984739679 is an apocalyptic number.

666984739679 is a deficient number, since it is larger than the sum of its proper divisors (5097121).

666984739679 is a wasteful number, since it uses less digits than its factorization.

666984739679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5097120.

The product of its digits is 4444263936, while the sum is 80.

The spelling of 666984739679 in words is "six hundred sixty-six billion, nine hundred eighty-four million, seven hundred thirty-nine thousand, six hundred seventy-nine".