665516606505 has 16 divisors (see below), whose sum is σ = 1064942873280. Its totient is φ = 354903422528.

The previous prime is 665516606399. The next prime is 665516606519. The reversal of 665516606505 is 505606615566.

It is a cyclic number.

It is not a de Polignac number, because 665516606505 - 2²⁰ = 665515557929 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2280795 + ... + 2555984.

It is an arithmetic number, because the mean of its divisors is an integer number (66558929580).

Almost surely, 2^665516606505 is an apocalyptic number.

It is an amenable number.

665516606505 is a deficient number, since it is larger than the sum of its proper divisors (399426266775).

665516606505 is a wasteful number, since it uses less digits than its factorization.

665516606505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4845960.

The product of its (nonzero) digits is 4860000, while the sum is 51.

The spelling of 665516606505 in words is "six hundred sixty-five billion, five hundred sixteen million, six hundred six thousand, five hundred five".