1222222121 has 2 divisors, whose sum is σ = 1222222122. Its totient is φ = 1222222120.

The previous prime is 1222222103. The next prime is 1222222171. The reversal of 1222222121 is 1212222221.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1220733721 + 1488400 = 34939^2 + 1220^2 .

It is a cyclic number.

It is not a de Polignac number, because 1222222121 - 2¹⁴ = 1222205737 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1222222121.

It is not a weakly prime, because it can be changed into another prime (1222222171) 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 as a sum of consecutive naturals, namely, 611111060 + 611111061.

It is an arithmetic number, because the mean of its divisors is an integer number (611111061).

Almost surely, 2^1222222121 is an apocalyptic number.

It is an amenable number.

1222222121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1222222121 is an equidigital number, since it uses as much as digits as its factorization.

1222222121 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 1222222121 is about 34960.2934913310. The cubic root of 1222222121 is about 1069.1780804828.

Adding to 1222222121 its reverse (1212222221), we get a palindrome (2434444342).

It can be divided in two parts, 12222 and 22121, that added together give a palindrome (34343).

The spelling of 1222222121 in words is "one billion, two hundred twenty-two million, two hundred twenty-two thousand, one hundred twenty-one".