665116000561 has 4 divisors (see below), whose sum is σ = 665123854324. Its totient is φ = 665108146800.

The previous prime is 665116000547. The next prime is 665116000603. The reversal of 665116000561 is 165000611566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 292552256161 + 372563744400 = 540881^2 + 610380^2 .

It is a cyclic number.

It is not a de Polignac number, because 665116000561 - 2⁷ = 665116000433 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 665116000561.

It is not an unprimeable number, because it can be changed into a prime (665116000501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3798450 + ... + 3969691.

It is an arithmetic number, because the mean of its divisors is an integer number (166280963581).

Almost surely, 2^665116000561 is an apocalyptic number.

It is an amenable number.

665116000561 is a deficient number, since it is larger than the sum of its proper divisors (7853763).

665116000561 is an equidigital number, since it uses as much as digits as its factorization.

665116000561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7853762.

The product of its (nonzero) digits is 32400, while the sum is 37.

The spelling of 665116000561 in words is "six hundred sixty-five billion, one hundred sixteen million, five hundred sixty-one", and thus it is an aban number.