665844411161 has 16 divisors (see below), whose sum is σ = 719586063360. Its totient is φ = 614219686080.

The previous prime is 665844411157. The next prime is 665844411173. The reversal of 665844411161 is 161114448566.

It is a cyclic number.

It is not a de Polignac number, because 665844411161 - 2² = 665844411157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665844411191) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2750 + ... + 1153991.

It is an arithmetic number, because the mean of its divisors is an integer number (44974128960).

Almost surely, 2^665844411161 is an apocalyptic number.

It is an amenable number.

665844411161 is a deficient number, since it is larger than the sum of its proper divisors (53741652199).

665844411161 is a wasteful number, since it uses less digits than its factorization.

665844411161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1157656.

The product of its digits is 552960, while the sum is 47.

The spelling of 665844411161 in words is "six hundred sixty-five billion, eight hundred forty-four million, four hundred eleven thousand, one hundred sixty-one".