66917767668165 has 24 divisors (see below), whose sum is σ = 119732435916288. Its totient is φ = 34538202666720.

The previous prime is 66917767668097. The next prime is 66917767668197. The reversal of 66917767668165 is 56186676771966.

It is not a de Polignac number, because 66917767668165 - 2⁸ = 66917767667909 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23984861569 + ... + 23984864358.

It is an arithmetic number, because the mean of its divisors is an integer number (4988851496512).

Almost surely, 2^{66917767668165} is an apocalyptic number.

It is an amenable number.

66917767668165 is a deficient number, since it is larger than the sum of its proper divisors (52814668248123).

66917767668165 is a wasteful number, since it uses less digits than its factorization.

66917767668165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47969725969 (or 47969725966 counting only the distinct ones).

The product of its digits is 5761082880, while the sum is 81.

The spelling of 66917767668165 in words is "sixty-six trillion, nine hundred seventeen billion, seven hundred sixty-seven million, six hundred sixty-eight thousand, one hundred sixty-five".