22109221 has 2 divisors, whose sum is σ = 22109222. Its totient is φ = 22109220.

The previous prime is 22109189. The next prime is 22109237. The reversal of 22109221 is 12290122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21986721 + 122500 = 4689^2 + 350^2 .

It is a cyclic number.

It is not a de Polignac number, because 22109221 - 2⁵ = 22109189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22109261) 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 as a sum of consecutive naturals, namely, 11054610 + 11054611.

It is an arithmetic number, because the mean of its divisors is an integer number (11054611).

Almost surely, 2^22109221 is an apocalyptic number.

It is an amenable number.

22109221 is a deficient number, since it is larger than the sum of its proper divisors (1).

22109221 is an equidigital number, since it uses as much as digits as its factorization.

22109221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 22109221 is about 4702.0443426237. The cubic root of 22109221 is about 280.6668671155. Note that the first 3 decimals are identical.

Adding to 22109221 its reverse (12290122), we get a palindrome (34399343).

The spelling of 22109221 in words is "twenty-two million, one hundred nine thousand, two hundred twenty-one".