22118221 has 4 divisors (see below), whose sum is σ = 22831744. Its totient is φ = 21404700.

The previous prime is 22118179. The next prime is 22118227. The reversal of 22118221 is 12281122.

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 a cyclic number.

It is not a de Polignac number, because 22118221 - 2⁷ = 22118093 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 (22118227) 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, 356715 + ... + 356776.

It is an arithmetic number, because the mean of its divisors is an integer number (5707936).

Almost surely, 2^22118221 is an apocalyptic number.

It is an amenable number.

22118221 is a deficient number, since it is larger than the sum of its proper divisors (713523).

22118221 is an equidigital number, since it uses as much as digits as its factorization.

22118221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 713522.

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

The square root of 22118221 is about 4703.0012757812. The cubic root of 22118221 is about 280.7049456338.

Adding to 22118221 its reverse (12281122), we get a palindrome (34399343).

The spelling of 22118221 in words is "twenty-two million, one hundred eighteen thousand, two hundred twenty-one".