315209 has 4 divisors (see below), whose sum is σ = 316416. Its totient is φ = 314004.

The previous prime is 315199. The next prime is 315223. The reversal of 315209 is 902513.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 902513 = 17 ⋅53089.

It is a cyclic number.

It is not a de Polignac number, because 315209 - 2⁴ = 315193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (315269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29 + ... + 794.

It is an arithmetic number, because the mean of its divisors is an integer number (79104).

2³¹⁵²⁰⁹ is an apocalyptic number.

It is an amenable number.

315209 is a deficient number, since it is larger than the sum of its proper divisors (1207).

315209 is an equidigital number, since it uses as much as digits as its factorization.

315209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1206.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 315209 is about 561.4347691406. The cubic root of 315209 is about 68.0559660364.

The spelling of 315209 in words is "three hundred fifteen thousand, two hundred nine".