308209 has 4 divisors (see below), whose sum is σ = 336240. Its totient is φ = 280180.

The previous prime is 308153. The next prime is 308213. The reversal of 308209 is 902803.

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 an emirpimes, since its reverse is a distinct semiprime: 902803 = 11 ⋅82073.

It is a cyclic number.

It is not a de Polignac number, because 308209 - 2⁷ = 308081 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 308209.

It is not an unprimeable number, because it can be changed into a prime (308219) 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 in 3 ways as a sum of consecutive naturals, for example, 13999 + ... + 14020.

It is an arithmetic number, because the mean of its divisors is an integer number (84060).

2³⁰⁸²⁰⁹ is an apocalyptic number.

It is an amenable number.

308209 is a deficient number, since it is larger than the sum of its proper divisors (28031).

308209 is a wasteful number, since it uses less digits than its factorization.

308209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28030.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 308209 is about 555.1657410179. The cubic root of 308209 is about 67.5484060649.

The spelling of 308209 in words is "three hundred eight thousand, two hundred nine".