306809 has 2 divisors, whose sum is σ = 306810. Its totient is φ = 306808.

The previous prime is 306781. The next prime is 306821. The reversal of 306809 is 908603.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162409 + 144400 = 403^2 + 380^2 .

It is an emirp because it is prime and its reverse (908603) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-306809 is a prime.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 306809.

It is not a weakly prime, because it can be changed into another prime (306829) 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 as a sum of consecutive naturals, namely, 153404 + 153405.

It is an arithmetic number, because the mean of its divisors is an integer number (153405).

2³⁰⁶⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

306809 is a deficient number, since it is larger than the sum of its proper divisors (1).

306809 is an equidigital number, since it uses as much as digits as its factorization.

306809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 306809 is about 553.9034211846. The cubic root of 306809 is about 67.4459741456.

The spelling of 306809 in words is "three hundred six thousand, eight hundred nine".