1321443209 has 2 divisors, whose sum is σ = 1321443210. Its totient is φ = 1321443208.

The previous prime is 1321443163. The next prime is 1321443251. The reversal of 1321443209 is 9023441231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 743761984 + 577681225 = 27272^2 + 24035^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321443209 is a prime.

It is a super-2 number, since 2×1321443209² = 3492424309224435362, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1321443289) 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, 660721604 + 660721605.

It is an arithmetic number, because the mean of its divisors is an integer number (660721605).

Almost surely, 2^1321443209 is an apocalyptic number.

It is an amenable number.

1321443209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321443209 is an equidigital number, since it uses as much as digits as its factorization.

1321443209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 1321443209 is about 36351.6603334703. The cubic root of 1321443209 is about 1097.3609488235.

The spelling of 1321443209 in words is "one billion, three hundred twenty-one million, four hundred forty-three thousand, two hundred nine".