117805209 has 4 divisors (see below), whose sum is σ = 157073616. Its totient is φ = 78536804.

The previous prime is 117805201. The next prime is 117805231. The reversal of 117805209 is 902508711.

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.

It is a cyclic number.

It is not a de Polignac number, because 117805209 - 2³ = 117805201 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 117805209.

It is not an unprimeable number, because it can be changed into a prime (117805201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19634199 + ... + 19634204.

It is an arithmetic number, because the mean of its divisors is an integer number (39268404).

Almost surely, 2^117805209 is an apocalyptic number.

It is an amenable number.

117805209 is a deficient number, since it is larger than the sum of its proper divisors (39268407).

117805209 is an equidigital number, since it uses as much as digits as its factorization.

117805209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39268406.

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 117805209 is about 10853.8108054268. The cubic root of 117805209 is about 490.2167706722.

The spelling of 117805209 in words is "one hundred seventeen million, eight hundred five thousand, two hundred nine".