I'm not sure, but for Mandarin Chinese, "yi" means 1. (So, Chinese people count 1, 2, 3, ... as yi, er, san... .) "Yige" means "one (unit) of ..." like "yigeren" means one person.
The right word in Greek is ένα (ena). Ένας (Enas) is the male noun. For example you can say ένας άντρας (enas antras)= one man. I know it's a bit weird but in Greek all the nouns are categorized as males/females/neutral.