13221209 has 2 divisors, whose sum is σ = 13221210. Its totient is φ = 13221208.

The previous prime is 13221199. The next prime is 13221227. The reversal of 13221209 is 90212231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12581209 + 640000 = 3547^2 + 800^2 .

It is a cyclic number.

It is not a de Polignac number, because 13221209 - 2⁸ = 13220953 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (13221269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6610604 + 6610605.

It is an arithmetic number, because the mean of its divisors is an integer number (6610605).

Almost surely, 2^13221209 is an apocalyptic number.

It is an amenable number.

13221209 is a deficient number, since it is larger than the sum of its proper divisors (1).

13221209 is an equidigital number, since it uses as much as digits as its factorization.

13221209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 13221209 is about 3636.0980459828. The cubic root of 13221209 is about 236.4596578620.

The spelling of 13221209 in words is "thirteen million, two hundred twenty-one thousand, two hundred nine".