2221211221 has 2 divisors, whose sum is σ = 2221211222. Its totient is φ = 2221211220.

The previous prime is 2221211189. The next prime is 2221211227. The reversal of 2221211221 is 1221121222.

It is a happy number.

2221211221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2081640625 + 139570596 = 45625^2 + 11814^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221211221 - 2⁵ = 2221211189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2221211195 and 2221211204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2221211227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110605610 + 1110605611.

It is an arithmetic number, because the mean of its divisors is an integer number (1110605611).

Almost surely, 2^2221211221 is an apocalyptic number.

It is an amenable number.

2221211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221211221 is an equidigital number, since it uses as much as digits as its factorization.

2221211221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64, while the sum is 16.

The square root of 2221211221 is about 47129.7275718840. The cubic root of 2221211221 is about 1304.7579535724.

Adding to 2221211221 its reverse (1221121222), we get a palindrome (3442332443).

It can be divided in two parts, 22212 and 11221, that added together give a palindrome (33433).

The spelling of 2221211221 in words is "two billion, two hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".