66166611666165 has 40 divisors (see below), whose sum is σ = 118654386792480. Its totient is φ = 35275587503328.

The previous prime is 66166611666151. The next prime is 66166611666187. The reversal of 66166611666165 is 56166611666166.

It is not a de Polignac number, because 66166611666165 - 2⁸ = 66166611665909 is a prime.

It is a super-3 number, since 3×66166611666165³ (a number of 42 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 29644119 + ... + 31797908.

It is an arithmetic number, because the mean of its divisors is an integer number (2966359669812).

Almost surely, 2^{66166611666165} is an apocalyptic number.

It is an amenable number.

66166611666165 is a deficient number, since it is larger than the sum of its proper divisors (52487775126315).

66166611666165 is a wasteful number, since it uses less digits than its factorization.

66166611666165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61444703 (or 61444694 counting only the distinct ones).

The product of its digits is 50388480, while the sum is 63.

Subtracting from 66166611666165 its reverse (56166611666166), we obtain a palindrome (9999999999999).

The spelling of 66166611666165 in words is "sixty-six trillion, one hundred sixty-six billion, six hundred eleven million, six hundred sixty-six thousand, one hundred sixty-five".