165181 has 2 divisors, whose sum is σ = 165182. Its totient is φ = 165180.

The previous prime is 165173. The next prime is 165203. The reversal of 165181 is 181561.

165181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (165203) can be obtained adding 165181 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164025 + 1156 = 405^2 + 34^2 .

It is a cyclic number.

It is not a de Polignac number, because 165181 - 2³ = 165173 is a prime.

It is a super-2 number, since 2×165181² = 54569525522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82590 + 82591.

It is an arithmetic number, because the mean of its divisors is an integer number (82591).

2¹⁶⁵¹⁸¹ is an apocalyptic number.

It is an amenable number.

165181 is a deficient number, since it is larger than the sum of its proper divisors (1).

165181 is an equidigital number, since it uses as much as digits as its factorization.

165181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 240, while the sum is 22.

The square root of 165181 is about 406.4246547640. The cubic root of 165181 is about 54.8681137506.

The spelling of 165181 in words is "one hundred sixty-five thousand, one hundred eighty-one".