161165 has 4 divisors (see below), whose sum is σ = 193404. Its totient is φ = 128928.

The previous prime is 161159. The next prime is 161167. The reversal of 161165 is 561161.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 88804 + 72361 = 298^2 + 269^2 .

It is a cyclic number.

It is not a de Polignac number, because 161165 - 2⁴ = 161149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16112 + ... + 16121.

It is an arithmetic number, because the mean of its divisors is an integer number (48351).

2¹⁶¹¹⁶⁵ is an apocalyptic number.

It is an amenable number.

161165 is a deficient number, since it is larger than the sum of its proper divisors (32239).

161165 is an equidigital number, since it uses as much as digits as its factorization.

161165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32238.

The product of its digits is 180, while the sum is 20.

The square root of 161165 is about 401.4536087769. The cubic root of 161165 is about 54.4197961762.

It can be divided in two parts, 161 and 165, that multiplied together give a triangular number (26565 = T₂₃₀).

The spelling of 161165 in words is "one hundred sixty-one thousand, one hundred sixty-five".