66655500165 has 24 divisors (see below), whose sum is σ = 115623764568. Its totient is φ = 35522657280.

The previous prime is 66655500133. The next prime is 66655500181. The reversal of 66655500165 is 56100555666.

It can be written as a sum of positive squares in 4 ways, for example, as 3824061921 + 62831438244 = 61839^2 + 250662^2 .

It is not a de Polignac number, because 66655500165 - 2⁵ = 66655500133 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66655500165.

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, 501204 + ... + 620093.

It is an arithmetic number, because the mean of its divisors is an integer number (4817656857).

Almost surely, 2^66655500165 is an apocalyptic number.

It is an amenable number.

66655500165 is a deficient number, since it is larger than the sum of its proper divisors (48968264403).

66655500165 is a wasteful number, since it uses less digits than its factorization.

66655500165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1122629 (or 1122626 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 45.

The spelling of 66655500165 in words is "sixty-six billion, six hundred fifty-five million, five hundred thousand, one hundred sixty-five".