I’ve written some blog posts in the past where I explain how I use Facebook ads to estimate how many Facebook users there are in a particular country. Here’s a September 2017 update for Armenia!
As of September 2017, there are about 1,100,000 Facebook users in Armenia, according to Facebook. That is 37% of the total population, and 34% of the population over age 14 (Facebook technically isn’t available to those under 13.)
As far as gender, 36% of the total male population, or 46% of males over age 14 are on Facebook. 40% of the total female population, or 49% of the female 14+ population. So there are some gender differences, but probably within the margin of error.
Just looking at the 15-24 year olds, 89% of them are on the site, 82% of young men and 97% of young women.