Adding to 2165 its reverse (5612), we get a palindrome (7777).
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 is a cyclic number.
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 an amenable number.
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 square root of 2165 is about 46.5295604965. The cubic root of 2165 is about 12.9365746886.
The spelling of 2165 in words is "two thousand, one hundred sixty-five".