1221333121 has 2 divisors, whose sum is σ = 1221333122. Its totient is φ = 1221333120.

The previous prime is 1221333073. The next prime is 1221333137. The reversal of 1221333121 is 1213331221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 838739521 + 382593600 = 28961^2 + 19560^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221333121 - 2⁷ = 1221332993 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221333221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610666560 + 610666561.

It is an arithmetic number, because the mean of its divisors is an integer number (610666561).

Almost surely, 2^1221333121 is an apocalyptic number.

It is an amenable number.

1221333121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221333121 is an equidigital number, since it uses as much as digits as its factorization.

1221333121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 19.

The square root of 1221333121 is about 34947.5767543331. The cubic root of 1221333121 is about 1068.9187904996.

Adding to 1221333121 its reverse (1213331221), we get a palindrome (2434664342).

It can be divided in two parts, 1 and 221333121, that added together give a palindrome (221333122).

The spelling of 1221333121 in words is "one billion, two hundred twenty-one million, three hundred thirty-three thousand, one hundred twenty-one".