10809 has 6 divisors (see below), whose sum is σ = 15626. Its totient is φ = 7200.

The previous prime is 10799. The next prime is 10831. The reversal of 10809 is 90801.

10809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 5625 + 5184 = 75^2 + 72^2 .

It is not a de Polignac number, because 10809 - 2¹¹ = 8761 is a prime.

It is a Duffinian number.

10809 is a lucky number.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 10791 and 10800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10859) 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 5 ways as a sum of consecutive naturals, for example, 592 + ... + 609.

2¹⁰⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

10809 is a deficient number, since it is larger than the sum of its proper divisors (4817).

10809 is a wasteful number, since it uses less digits than its factorization.

10809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1207 (or 1204 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 10809 is about 103.9663407070. The cubic root of 10809 is about 22.1103273396.

It can be divided in two parts, 1080 and 9, that added together give a square (1089 = 33²).

The spelling of 10809 in words is "ten thousand, eight hundred nine".