22811221 has 4 divisors (see below), whose sum is σ = 22927212. Its totient is φ = 22695232.

The previous prime is 22811209. The next prime is 22811233. The reversal of 22811221 is 12211822.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (22811209) and next prime (22811233).

It can be written as a sum of positive squares in 2 ways, for example, as 10491121 + 12320100 = 3239^2 + 3510^2 .

It is a cyclic number.

It is not a de Polignac number, because 22811221 - 2⁵ = 22811189 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 (22811251) 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 3 ways as a sum of consecutive naturals, for example, 57700 + ... + 58093.

It is an arithmetic number, because the mean of its divisors is an integer number (5731803).

Almost surely, 2^22811221 is an apocalyptic number.

It is an amenable number.

22811221 is a deficient number, since it is larger than the sum of its proper divisors (115991).

22811221 is a wasteful number, since it uses less digits than its factorization.

22811221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115990.

The product of its digits is 128, while the sum is 19.

The square root of 22811221 is about 4776.1093999196. The cubic root of 22811221 is about 283.6064981075.

It can be divided in two parts, 22811 and 221, that added together give a palindrome (23032).

The spelling of 22811221 in words is "twenty-two million, eight hundred eleven thousand, two hundred twenty-one".