22221211221 has 20 divisors (see below), whose sum is σ = 36212345664. Its totient is φ = 13467400200.

The previous prime is 22221211217. The next prime is 22221211247. The reversal of 22221211221 is 12211212222.

It is a happy number.

22221211221 is a `hidden beast` number, since 222 + 212 + 11 + 221 = 666.

It is not a de Polignac number, because 22221211221 - 2² = 22221211217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22221211194 and 22221211203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22221211291) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12468925 + ... + 12470706.

Almost surely, 2^22221211221 is an apocalyptic number.

It is an amenable number.

22221211221 is a deficient number, since it is larger than the sum of its proper divisors (13991134443).

22221211221 is a wasteful number, since it uses less digits than its factorization.

22221211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24939654 (or 24939645 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

Adding to 22221211221 its reverse (12211212222), we get a palindrome (34432423443).

The spelling of 22221211221 in words is "twenty-two billion, two hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".