12809 has 2 divisors, whose sum is σ = 12810.
Its totient is φ = 12808.
The previous prime is 12799. The next prime is 12821. The reversal of 12809 is 90821.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 10000 + 2809 = 100^2 + 53^2
It is an emirp because it is prime and its reverse (90821) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 12809 - 28 = 12553 is a prime.
It is a Chen prime.
It is a plaindrome in base 15.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (12829) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (5) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6404 + 6405.
It is an arithmetic number, because the mean of its divisors is an integer number (6405).
212809 is an apocalyptic number.
It is an amenable number.
12809 is a deficient number, since it is larger than the sum of its proper divisors (1).
12809 is an equidigital number, since it uses as much as digits as its factorization.
12809 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 144, while the sum is 20.
The square root of 12809 is about 113.1768527571.
The cubic root of 12809 is about 23.3976231545.
The spelling of 12809 in words is "twelve thousand, eight hundred nine".