16809 has 8 divisors (see below), whose sum is σ = 24192. Its totient is φ = 10320.

The previous prime is 16787. The next prime is 16811. The reversal of 16809 is 90861.

16809 is nontrivially palindromic in base 12.

16809 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16809 - 2⁸ = 16553 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 177 + ... + 254.

It is an arithmetic number, because the mean of its divisors is an integer number (3024).

2¹⁶⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

16809 is a deficient number, since it is larger than the sum of its proper divisors (7383).

16809 is a wasteful number, since it uses less digits than its factorization.

16809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 16809 is about 129.6495275734. The cubic root of 16809 is about 25.6161559803.

The spelling of 16809 in words is "sixteen thousand, eight hundred nine".