1321222121 has 2 divisors, whose sum is σ = 1321222122. Its totient is φ = 1321222120.

The previous prime is 1321222117. The next prime is 1321222127. The reversal of 1321222121 is 1212221231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1311236521 + 9985600 = 36211^2 + 3160^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321222121 - 2² = 1321222117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321222121.

It is not a weakly prime, because it can be changed into another prime (1321222127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660611060 + 660611061.

It is an arithmetic number, because the mean of its divisors is an integer number (660611061).

Almost surely, 2^1321222121 is an apocalyptic number.

It is an amenable number.

1321222121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321222121 is an equidigital number, since it uses as much as digits as its factorization.

1321222121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 17.

The square root of 1321222121 is about 36348.6192447526. The cubic root of 1321222121 is about 1097.2997463272.

Adding to 1321222121 its reverse (1212221231), we get a palindrome (2533443352).

The spelling of 1321222121 in words is "one billion, three hundred twenty-one million, two hundred twenty-two thousand, one hundred twenty-one".