33809 has 2 divisors, whose sum is σ = 33810. Its totient is φ = 33808.

The previous prime is 33797. The next prime is 33811. The reversal of 33809 is 90833.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29584 + 4225 = 172^2 + 65^2 .

It is an emirp because it is prime and its reverse (90833) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-33809 is a prime.

It is a super-2 number, since 2×33809² = 2286096962, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 33811, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a Curzon number.

It is a plaindrome in base 11.

It is a nialpdrome in base 16.

It is not a weakly prime, because it can be changed into another prime (33829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16904 + 16905.

It is an arithmetic number, because the mean of its divisors is an integer number (16905).

2³³⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

33809 is a deficient number, since it is larger than the sum of its proper divisors (1).

33809 is an equidigital number, since it uses as much as digits as its factorization.

33809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 33809 is about 183.8722382525. The cubic root of 33809 is about 32.3353407429.

The spelling of 33809 in words is "thirty-three thousand, eight hundred nine".