2215665 has 24 divisors (see below), whose sum is σ = 3917160. Its totient is φ = 1158144.

The previous prime is 2215651. The next prime is 2215667. The reversal of 2215665 is 5665122.

It can be written as a sum of positive squares in 4 ways, for example, as 28224 + 2187441 = 168^2 + 1479^2 .

It is not a de Polignac number, because 2215665 - 2⁷ = 2215537 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2215667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1921 + ... + 2849.

It is an arithmetic number, because the mean of its divisors is an integer number (163215).

2^2215665 is an apocalyptic number.

It is an amenable number.

2215665 is a deficient number, since it is larger than the sum of its proper divisors (1701495).

2215665 is a wasteful number, since it uses less digits than its factorization.

2215665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 993 (or 990 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 2215665 is about 1488.5110009671. The cubic root of 2215665 is about 130.3671083000.

It can be divided in two parts, 221 and 5665, that added together give a triangular number (5886 = T₁₀₈).

The spelling of 2215665 in words is "two million, two hundred fifteen thousand, six hundred sixty-five".