3809 has 4 divisors (see below), whose sum is σ = 4116. Its totient is φ = 3504.

The previous prime is 3803. The next prime is 3821. The reversal of 3809 is 9083.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9083 = 31 ⋅293.

It can be written as a sum of positive squares in 2 ways, for example, as 2209 + 1600 = 47^2 + 40^2 .

It is a cyclic number.

It is not a de Polignac number, because 3809 - 2⁴ = 3793 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12 and base 15.

It is a nialpdrome in base 16.

It is a zygodrome in base 12.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 3809.

It is not an unprimeable number, because it can be changed into a prime (3803) 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, 134 + ... + 159.

It is an arithmetic number, because the mean of its divisors is an integer number (1029).

2³⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

3809 is a deficient number, since it is larger than the sum of its proper divisors (307).

3809 is a wasteful number, since it uses less digits than its factorization.

3809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 3809 is about 61.7170964968. The cubic root of 3809 is about 15.6172174576.

The spelling of 3809 in words is "three thousand, eight hundred nine".