165206665 has 32 divisors (see below), whose sum is σ = 222507936. Its totient is φ = 116951040.

The previous prime is 165206647. The next prime is 165206669. The reversal of 165206665 is 566602561.

165206665 = 62² + 63² + ... + 791².

165206665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 16 ways, for example, as 18045504 + 147161161 = 4248^2 + 12131^2 .

It is not a de Polignac number, because 165206665 - 2⁷ = 165206537 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is not an unprimeable number, because it can be changed into a prime (165206669) 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, 175095 + ... + 176035.

It is an arithmetic number, because the mean of its divisors is an integer number (6953373).

Almost surely, 2^165206665 is an apocalyptic number.

It is an amenable number.

165206665 is a deficient number, since it is larger than the sum of its proper divisors (57301271).

165206665 is a wasteful number, since it uses less digits than its factorization.

165206665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1069.

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 165206665 is about 12853.2744855154. The cubic root of 165206665 is about 548.7095531475.

The spelling of 165206665 in words is "one hundred sixty-five million, two hundred six thousand, six hundred sixty-five".