13218209 has 2 divisors, whose sum is σ = 13218210. Its totient is φ = 13218208.

The previous prime is 13218199. The next prime is 13218263. The reversal of 13218209 is 90281231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10705984 + 2512225 = 3272^2 + 1585^2 .

It is an emirp because it is prime and its reverse (90281231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13218209 - 2¹⁶ = 13152673 is a prime.

It is a Chen prime.

It is equal to p₈₆₂₅₁₄ and since 13218209 and 862514 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (13218269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6609104 + 6609105.

It is an arithmetic number, because the mean of its divisors is an integer number (6609105).

Almost surely, 2^13218209 is an apocalyptic number.

It is an amenable number.

13218209 is a deficient number, since it is larger than the sum of its proper divisors (1).

13218209 is an equidigital number, since it uses as much as digits as its factorization.

13218209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 13218209 is about 3635.6854924484. The cubic root of 13218209 is about 236.4417716351.

The spelling of 13218209 in words is "thirteen million, two hundred eighteen thousand, two hundred nine".