103809 has 4 divisors (see below), whose sum is σ = 138416.
Its totient is φ = 69204.
The previous prime is 103801. The next prime is 103811. The reversal of 103809 is 908301.
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, and also an emirpimes, since its reverse is a distinct semiprime: 908301 = 3 ⋅302767.
It is not a de Polignac number, because 103809 - 23 = 103801 is a prime.
It is a D-number.
It is a Duffinian number.
It is a Curzon number.
It is not an unprimeable number, because it can be changed into a prime (103801) 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, 17299 + ... + 17304.
It is an arithmetic number, because the mean of its divisors is an integer number (34604).
2103809 is an apocalyptic number.
It is an amenable number.
103809 is a deficient number, since it is larger than the sum of its proper divisors (34607).
103809 is an equidigital number, since it uses as much as digits as its factorization.
103809 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 34606.
The product of its (nonzero) digits is 216, while the sum is 21.
The square root of 103809 is about 322.1940409132.
The cubic root of 103809 is about 46.9978873352.
The spelling of 103809 in words is "one hundred three thousand, eight hundred nine".