306309 has 4 divisors (see below), whose sum is σ = 408416. Its totient is φ = 204204.

The previous prime is 306301. The next prime is 306329. The reversal of 306309 is 903603.

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.

It is not a de Polignac number, because 306309 - 2³ = 306301 is a prime.

It is a D-number.

It is a Duffinian number.

306309 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (306301) 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, 51049 + ... + 51054.

It is an arithmetic number, because the mean of its divisors is an integer number (102104).

2³⁰⁶³⁰⁹ is an apocalyptic number.

It is an amenable number.

306309 is a deficient number, since it is larger than the sum of its proper divisors (102107).

306309 is a wasteful number, since it uses less digits than its factorization.

306309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102106.

The product of its (nonzero) digits is 486, while the sum is 21.

The square root of 306309 is about 553.4518949285. The cubic root of 306309 is about 67.4093158088.

The spelling of 306309 in words is "three hundred six thousand, three hundred nine".