2222211221 has 2 divisors, whose sum is σ = 2222211222. Its totient is φ = 2222211220.

The previous prime is 2222211163. The next prime is 2222211227. The reversal of 2222211221 is 1221122222.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1351371121 + 870840100 = 36761^2 + 29510^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2222211221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2222211221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2222211227) 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, 1111105610 + 1111105611.

It is an arithmetic number, because the mean of its divisors is an integer number (1111105611).

Almost surely, 2^2222211221 is an apocalyptic number.

It is an amenable number.

2222211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2222211221 is an equidigital number, since it uses as much as digits as its factorization.

2222211221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 128, while the sum is 17.

The square root of 2222211221 is about 47140.3353933762. The cubic root of 2222211221 is about 1304.9537269696.

Adding to 2222211221 its reverse (1221122222), we get a palindrome (3443333443).

The spelling of 2222211221 in words is "two billion, two hundred twenty-two million, two hundred eleven thousand, two hundred twenty-one".