My kitty bites... HARD?

So I have a little kitty.. He is about 10 months old. When he's in a playfull mood, he will jump up to me and bite me really hard. Also when I sleep I have to keep my legs under blankets the whole night, otherwise he'll come bite them when I'm sleeping... Is his behavior like this because I haven't gotten him neutered? Also, is there any way to train him to not bite me?