2165 has 4 divisors (see below), whose sum is σ = 2604. Its totient is φ = 1728.

The previous prime is 2161. The next prime is 2179. The reversal of 2165 is 5612.

2165 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 484 + 1681 = 22^2 + 41^2 .

It is a cyclic number.

It is not a de Polignac number, because 2165 - 2² = 2161 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a nialpdrome in base 13, base 15 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161) 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, 212 + ... + 221.

It is an arithmetic number, because the mean of its divisors is an integer number (651).

It is an amenable number.

2165 is a deficient number, since it is larger than the sum of its proper divisors (439).

2165 is an equidigital number, since it uses as much as digits as its factorization.

2165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438.

The product of its digits is 60, while the sum is 14.

The square root of 2165 is about 46.5295604965. The cubic root of 2165 is about 12.9365746886.

Adding to 2165 its reverse (5612), we get a palindrome (7777).

The spelling of 2165 in words is "two thousand, one hundred sixty-five".