22211211221 has 4 divisors (see below), whose sum is σ = 22630290732. Its totient is φ = 21792131712.

The previous prime is 22211211203. The next prime is 22211211227. The reversal of 22211211221 is 12211211222.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8076616900 + 14134594321 = 89870^2 + 118889^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22211211221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 22211211221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22211211227) 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, 209539676 + ... + 209539781.

It is an arithmetic number, because the mean of its divisors is an integer number (5657572683).

Almost surely, 2^22211211221 is an apocalyptic number.

It is an amenable number.

22211211221 is a deficient number, since it is larger than the sum of its proper divisors (419079511).

22211211221 is an equidigital number, since it uses as much as digits as its factorization.

22211211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419079510.

The product of its digits is 64, while the sum is 17.

Adding to 22211211221 its reverse (12211211222), we get a palindrome (34422422443).

Subtracting from 22211211221 its reverse (12211211222), we obtain a palindrome (9999999999).

The spelling of 22211211221 in words is "twenty-two billion, two hundred eleven million, two hundred eleven thousand, two hundred twenty-one".