165585561 has 32 divisors (see below), whose sum is σ = 232657920. Its totient is φ = 104664000.

The previous prime is 165585529. The next prime is 165585569.

165585561 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 165585561 - 2⁵ = 165585529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165585569) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 924970 + ... + 925148.

It is an arithmetic number, because the mean of its divisors is an integer number (7270560).

Almost surely, 2^165585561 is an apocalyptic number.

It is an amenable number.

165585561 is a deficient number, since it is larger than the sum of its proper divisors (67072359).

165585561 is a wasteful number, since it uses less digits than its factorization.

165585561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397.

The product of its digits is 180000, while the sum is 42.

The square root of 165585561 is about 12868.0053232815. The cubic root of 165585561 is about 549.1287152454.

The spelling of 165585561 in words is "one hundred sixty-five million, five hundred eighty-five thousand, five hundred sixty-one".