809309 has 2 divisors, whose sum is σ = 809310. Its totient is φ = 809308.

The previous prime is 809297. The next prime is 809323. The reversal of 809309 is 903908.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 688900 + 120409 = 830^2 + 347^2 .

It is a cyclic number.

It is not a de Polignac number, because 809309 - 2¹² = 805213 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (809339) 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, 404654 + 404655.

It is an arithmetic number, because the mean of its divisors is an integer number (404655).

2⁸⁰⁹³⁰⁹ is an apocalyptic number.

It is an amenable number.

809309 is a deficient number, since it is larger than the sum of its proper divisors (1).

809309 is an equidigital number, since it uses as much as digits as its factorization.

809309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 809309 is about 899.6160292036. The cubic root of 809309 is about 93.1904602588.

The spelling of 809309 in words is "eight hundred nine thousand, three hundred nine".