22191221 has 12 divisors (see below), whose sum is σ = 25297920. Its totient is φ = 19403280.

The previous prime is 22191187. The next prime is 22191223. The reversal of 22191221 is 12219122.

It is a happy number.

It is not a de Polignac number, because 22191221 - 2¹⁸ = 21929077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22191193 and 22191202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22191223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 245 + ... + 6666.

It is an arithmetic number, because the mean of its divisors is an integer number (2108160).

Almost surely, 2^22191221 is an apocalyptic number.

It is an amenable number.

22191221 is a deficient number, since it is larger than the sum of its proper divisors (3106699).

22191221 is a wasteful number, since it uses less digits than its factorization.

22191221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6956 (or 6943 counting only the distinct ones).

The product of its digits is 144, while the sum is 20.

The square root of 22191221 is about 4710.7558841443. The cubic root of 22191221 is about 281.0134237075.

The spelling of 22191221 in words is "twenty-two million, one hundred ninety-one thousand, two hundred twenty-one".