117809 has 2 divisors, whose sum is σ = 117810. Its totient is φ = 117808.

The previous prime is 117797. The next prime is 117811. The reversal of 117809 is 908711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115600 + 2209 = 340^2 + 47^2 .

It is an emirp because it is prime and its reverse (908711) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-117809 is a prime.

Together with 117811, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (117839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58904 + 58905.

It is an arithmetic number, because the mean of its divisors is an integer number (58905).

2¹¹⁷⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

117809 is a deficient number, since it is larger than the sum of its proper divisors (1).

117809 is an equidigital number, since it uses as much as digits as its factorization.

117809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 26.

The square root of 117809 is about 343.2331569065. The cubic root of 117809 is about 49.0222029047.

The spelling of 117809 in words is "one hundred seventeen thousand, eight hundred nine".