2165815 has 16 divisors (see below), whose sum is σ = 2730240. Its totient is φ = 1647360.

The previous prime is 2165809. The next prime is 2165819. The reversal of 2165815 is 5185612.

It is not a de Polignac number, because 2165815 - 2⁷ = 2165687 is a prime.

It is a super-2 number, since 2×2165815² = 9381509228450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2165819) 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, 13717 + ... + 13873.

It is an arithmetic number, because the mean of its divisors is an integer number (170640).

2^2165815 is an apocalyptic number.

2165815 is a deficient number, since it is larger than the sum of its proper divisors (564425).

2165815 is a wasteful number, since it uses less digits than its factorization.

2165815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282.

The product of its digits is 2400, while the sum is 28.

The square root of 2165815 is about 1471.6708191712. The cubic root of 2165815 is about 129.3819778106.

The spelling of 2165815 in words is "two million, one hundred sixty-five thousand, eight hundred fifteen".