165205 has 16 divisors (see below), whose sum is σ = 218880. Its totient is φ = 119232.

The previous prime is 165203. The next prime is 165211. The reversal of 165205 is 502561.

165205 = 124² + 125² + ... + 133².

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 165205 - 2¹ = 165203 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165203) 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, 3492 + ... + 3538.

It is an arithmetic number, because the mean of its divisors is an integer number (13680).

2¹⁶⁵²⁰⁵ is an apocalyptic number.

165205 is the 235-th octagonal number.

It is an amenable number.

165205 is a deficient number, since it is larger than the sum of its proper divisors (53675).

165205 is a wasteful number, since it uses less digits than its factorization.

165205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 165205 is about 406.4541794594. The cubic root of 165205 is about 54.8707709791.

Adding to 165205 its reverse (502561), we get a palindrome (667766).

The spelling of 165205 in words is "one hundred sixty-five thousand, two hundred five".