13938209 has 2 divisors, whose sum is σ = 13938210. Its totient is φ = 13938208.

The previous prime is 13938187. The next prime is 13938227. The reversal of 13938209 is 90283931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13667809 + 270400 = 3697^2 + 520^2 .

It is a cyclic number.

It is not a de Polignac number, because 13938209 - 2⁸ = 13937953 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (13938289) 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, 6969104 + 6969105.

It is an arithmetic number, because the mean of its divisors is an integer number (6969105).

Almost surely, 2^13938209 is an apocalyptic number.

It is an amenable number.

13938209 is a deficient number, since it is larger than the sum of its proper divisors (1).

13938209 is an equidigital number, since it uses as much as digits as its factorization.

13938209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 13938209 is about 3733.3910858628. The cubic root of 13938209 is about 240.6591198932.

The spelling of 13938209 in words is "thirteen million, nine hundred thirty-eight thousand, two hundred nine".