1221321169 has 2 divisors, whose sum is σ = 1221321170. Its totient is φ = 1221321168.

The previous prime is 1221321133. The next prime is 1221321187. The reversal of 1221321169 is 9611231221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 613057600 + 608263569 = 24760^2 + 24663^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221321169 - 2⁹ = 1221320657 is a prime.

It is a super-2 number, since 2×1221321169² = 2983250795695053122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221328169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610660584 + 610660585.

It is an arithmetic number, because the mean of its divisors is an integer number (610660585).

Almost surely, 2^1221321169 is an apocalyptic number.

It is an amenable number.

1221321169 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221321169 is an equidigital number, since it uses as much as digits as its factorization.

1221321169 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 28.

The square root of 1221321169 is about 34947.4057549341. The cubic root of 1221321169 is about 1068.9153036652.

The spelling of 1221321169 in words is "one billion, two hundred twenty-one million, three hundred twenty-one thousand, one hundred sixty-nine".