345209 has 4 divisors (see below), whose sum is σ = 351120. Its totient is φ = 339300.

The previous prime is 345193. The next prime is 345221. The reversal of 345209 is 902543.

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: 902543 = 23 ⋅39241.

It is a cyclic number.

It is not a de Polignac number, because 345209 - 2⁴ = 345193 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (345229) 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, 2867 + ... + 2984.

It is an arithmetic number, because the mean of its divisors is an integer number (87780).

2³⁴⁵²⁰⁹ is an apocalyptic number.

It is an amenable number.

345209 is a deficient number, since it is larger than the sum of its proper divisors (5911).

345209 is an equidigital number, since it uses as much as digits as its factorization.

345209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5910.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 345209 is about 587.5448919019. The cubic root of 345209 is about 70.1499506623.

The spelling of 345209 in words is "three hundred forty-five thousand, two hundred nine".