318209 has 2 divisors, whose sum is σ = 318210. Its totient is φ = 318208.

The previous prime is 318203. The next prime is 318211. The reversal of 318209 is 902813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 193600 + 124609 = 440^2 + 353^2 .

It is a cyclic number.

It is not a de Polignac number, because 318209 - 2¹² = 314113 is a prime.

Together with 318211, it forms a pair of twin primes.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 318209.

It is not a weakly prime, because it can be changed into another prime (318203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159104 + 159105.

It is an arithmetic number, because the mean of its divisors is an integer number (159105).

2³¹⁸²⁰⁹ is an apocalyptic number.

It is an amenable number.

318209 is a deficient number, since it is larger than the sum of its proper divisors (1).

318209 is an equidigital number, since it uses as much as digits as its factorization.

318209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 318209 is about 564.1001684098. The cubic root of 318209 is about 68.2711921023.

The spelling of 318209 in words is "three hundred eighteen thousand, two hundred nine".