2216565 has 40 divisors (see below), whose sum is σ = 4289208. Its totient is φ = 1088640.

The previous prime is 2216563. The next prime is 2216569. The reversal of 2216565 is 5656122.

2216565 is a `hidden beast` number, since 2 + 2 + 1 + 656 + 5 = 666.

2216565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

2216565 is a nontrivial binomial coefficient, being equal to C(2106, 2).

It can be written as a sum of positive squares in 4 ways, for example, as 116964 + 2099601 = 342^2 + 1449^2 .

It is not a de Polignac number, because 2216565 - 2¹ = 2216563 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2216563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5055 + ... + 5475.

2^2216565 is an apocalyptic number.

2216565 is the 2105-th triangular number and also the 1053-rd hexagonal number.

It is an amenable number.

2216565 is a deficient number, since it is larger than the sum of its proper divisors (2072643).

2216565 is a wasteful number, since it uses less digits than its factorization.

2216565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451 (or 442 counting only the distinct ones).

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

The square root of 2216565 is about 1488.8132858085. The cubic root of 2216565 is about 130.3847575557.

It can be divided in two parts, 221 and 6565, that added together give a triangular number (6786 = T₁₁₆).

The spelling of 2216565 in words is "two million, two hundred sixteen thousand, five hundred sixty-five".