165865165 has 8 divisors (see below), whose sum is σ = 200070648. Its totient is φ = 132003840.

The previous prime is 165865163. The next prime is 165865171. The reversal of 165865165 is 561568561.

It can be written as a sum of positive squares in 4 ways, for example, as 15729156 + 150136009 = 3966^2 + 12253^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165865165 - 2¹ = 165865163 is a prime.

It is a super-2 number, since 2×165865165² = 55022505920954450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165865163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84976 + ... + 86905.

It is an arithmetic number, because the mean of its divisors is an integer number (25008831).

Almost surely, 2^165865165 is an apocalyptic number.

It is an amenable number.

165865165 is a deficient number, since it is larger than the sum of its proper divisors (34205483).

165865165 is a wasteful number, since it uses less digits than its factorization.

165865165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172079.

The product of its digits is 216000, while the sum is 43.

The square root of 165865165 is about 12878.8650509274. The cubic root of 165865165 is about 549.4376235116.

The spelling of 165865165 in words is "one hundred sixty-five million, eight hundred sixty-five thousand, one hundred sixty-five".