As of May 2018, there are about 1,200,000 Facebook users in Armenia, according to Facebook. That is 40% of the total population, and 37% of the population over age 14 (Facebook technically isn’t available to those under 13.)
As far as gender, 40% of the total male population, or 51% of males over age 14 are on Facebook. 43% 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, 87% of them are on the site, 82% of young men and 92% of young women. (These numbers dropped a bit since last September).