13217221 has 2 divisors, whose sum is σ = 13217222. Its totient is φ = 13217220.

The previous prime is 13217209. The next prime is 13217233. The reversal of 13217221 is 12271231.

It is a balanced prime because it is at equal distance from previous prime (13217209) and next prime (13217233).

It can be written as a sum of positive squares in only one way, i.e., 13068225 + 148996 = 3615^2 + 386^2 .

It is a cyclic number.

It is not a de Polignac number, because 13217221 - 2²¹ = 11120069 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13217201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6608610 + 6608611.

It is an arithmetic number, because the mean of its divisors is an integer number (6608611).

Almost surely, 2^13217221 is an apocalyptic number.

It is an amenable number.

13217221 is a deficient number, since it is larger than the sum of its proper divisors (1).

13217221 is an equidigital number, since it uses as much as digits as its factorization.

13217221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 168, while the sum is 19.

The square root of 13217221 is about 3635.5496145700. The cubic root of 13217221 is about 236.4358805119.

Adding to 13217221 its reverse (12271231), we get a palindrome (25488452).

The spelling of 13217221 in words is "thirteen million, two hundred seventeen thousand, two hundred twenty-one".