666216644017 has 4 divisors (see below), whose sum is σ = 666383077360. Its totient is φ = 666050210676.

The previous prime is 666216643993. The next prime is 666216644029. The reversal of 666216644017 is 710446612666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666216644017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666216644057) 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, 83210667 + ... + 83218672.

It is an arithmetic number, because the mean of its divisors is an integer number (166595769340).

Almost surely, 2^666216644017 is an apocalyptic number.

It is an amenable number.

666216644017 is a deficient number, since it is larger than the sum of its proper divisors (166433343).

666216644017 is a wasteful number, since it uses less digits than its factorization.

666216644017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166433342.

The product of its (nonzero) digits is 1741824, while the sum is 49.

The spelling of 666216644017 in words is "six hundred sixty-six billion, two hundred sixteen million, six hundred forty-four thousand, seventeen".