312209 has 2 divisors, whose sum is σ = 312210. Its totient is φ = 312208.

The previous prime is 312203. The next prime is 312211. The reversal of 312209 is 902213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 305809 + 6400 = 553^2 + 80^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312209 is a prime.

It is a Sophie Germain prime.

Together with 312211, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 312209.

It is not a weakly prime, because it can be changed into another prime (312203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156104 + 156105.

It is an arithmetic number, because the mean of its divisors is an integer number (156105).

2³¹²²⁰⁹ is an apocalyptic number.

It is an amenable number.

312209 is a deficient number, since it is larger than the sum of its proper divisors (1).

312209 is an equidigital number, since it uses as much as digits as its factorization.

312209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 312209 is about 558.7566554413. The cubic root of 312209 is about 67.8393699926.

The spelling of 312209 in words is "three hundred twelve thousand, two hundred nine".