22521665 has 4 divisors (see below), whose sum is σ = 27026004. Its totient is φ = 18017328.

The previous prime is 22521647. The next prime is 22521673. The reversal of 22521665 is 56612522.

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 8690704 + 13830961 = 2948^2 + 3719^2 .

It is a cyclic number.

It is not a de Polignac number, because 22521665 - 2⁸ = 22521409 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2252162 + ... + 2252171.

It is an arithmetic number, because the mean of its divisors is an integer number (6756501).

Almost surely, 2^22521665 is an apocalyptic number.

It is an amenable number.

22521665 is a deficient number, since it is larger than the sum of its proper divisors (4504339).

22521665 is an equidigital number, since it uses as much as digits as its factorization.

22521665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4504338.

The product of its digits is 7200, while the sum is 29.

The square root of 22521665 is about 4745.6996322987. The cubic root of 22521665 is about 282.4013909106.

The spelling of 22521665 in words is "twenty-two million, five hundred twenty-one thousand, six hundred sixty-five".