22561221 has 4 divisors (see below), whose sum is σ = 30081632. Its totient is φ = 15040812.

The previous prime is 22561219. The next prime is 22561243. The reversal of 22561221 is 12216522.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 22561221 - 2¹ = 22561219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22561421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3760201 + ... + 3760206.

It is an arithmetic number, because the mean of its divisors is an integer number (7520408).

Almost surely, 2^22561221 is an apocalyptic number.

It is an amenable number.

22561221 is a deficient number, since it is larger than the sum of its proper divisors (7520411).

22561221 is an equidigital number, since it uses as much as digits as its factorization.

22561221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7520410.

The product of its digits is 480, while the sum is 21.

The square root of 22561221 is about 4749.8653665130. The cubic root of 22561221 is about 282.5666264133.

Adding to 22561221 its reverse (12216522), we get a palindrome (34777743).

The spelling of 22561221 in words is "twenty-two million, five hundred sixty-one thousand, two hundred twenty-one".