6809 has 4 divisors (see below), whose sum is σ = 7440. Its totient is φ = 6180.

The previous prime is 6803. The next prime is 6823. The reversal of 6809 is 9086.

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 a cyclic number.

It is not a de Polignac number, because 6809 - 2⁴ = 6793 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 (6803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 299 + ... + 320.

It is an arithmetic number, because the mean of its divisors is an integer number (1860).

It is an amenable number.

6809 is a deficient number, since it is larger than the sum of its proper divisors (631).

6809 is a wasteful number, since it uses less digits than its factorization.

6809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 6809 is about 82.5166649835. The cubic root of 6809 is about 18.9537193081.

Subtracting from 6809 its sum of digits (23), we obtain a triangular number (6786 = T₁₁₆).

The spelling of 6809 in words is "six thousand, eight hundred nine".