22521521 has 8 divisors (see below), whose sum is σ = 24616704. Its totient is φ = 20434320.

The previous prime is 22521511. The next prime is 22521523. The reversal of 22521521 is 12512522.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 22521521 - 2¹⁰ = 22520497 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22521493 and 22521502.

It is not an unprimeable number, because it can be changed into a prime (22521523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4991 + ... + 8363.

It is an arithmetic number, because the mean of its divisors is an integer number (3077088).

Almost surely, 2^22521521 is an apocalyptic number.

It is an amenable number.

22521521 is a deficient number, since it is larger than the sum of its proper divisors (2095183).

22521521 is a wasteful number, since it uses less digits than its factorization.

22521521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3991.

The product of its digits is 400, while the sum is 20.

The square root of 22521521 is about 4745.6844606442. The cubic root of 22521521 is about 282.4007890326.

It can be divided in two parts, 2252 and 1521, that added together give a palindrome (3773).

The spelling of 22521521 in words is "twenty-two million, five hundred twenty-one thousand, five hundred twenty-one".