666505560065 has 16 divisors (see below), whose sum is σ = 814955904000. Its totient is φ = 523106405952.

The previous prime is 666505560047. The next prime is 666505560073. The reversal of 666505560065 is 560065505666.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 666505560065 - 2⁸ = 666505559809 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 666505559995 and 666505560022.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3944996 + ... + 4110474.

It is an arithmetic number, because the mean of its divisors is an integer number (50934744000).

Almost surely, 2^666505560065 is an apocalyptic number.

It is an amenable number.

666505560065 is a deficient number, since it is larger than the sum of its proper divisors (148450343935).

666505560065 is a wasteful number, since it uses less digits than its factorization.

666505560065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180736.

The product of its (nonzero) digits is 4860000, while the sum is 50.

The spelling of 666505560065 in words is "six hundred sixty-six billion, five hundred five million, five hundred sixty thousand, sixty-five".