Yes .
Ateks are 14mm internal width (super narrow), but I´ve ran 2.1 tires on them without major problems. The sidewall bulges quite a bit and stability might suffer, but definitely rideable.There's various tables online showing rim width vs max tyre size, I'm guessing the Ateks are 17mm internal width or something like that? A 2.1 will be well within it's capabilities, you may want to check clearance to your frame though.
Not all tyres are created equal, one manufacturers 2.1 might measure the same as another's 1.9 and vice versa.
Over here we refer to them as "Dackelschneider", literal translation would be "wiener dog cutters"Crikey! 14mm?! No wonder they are lightweight, there's nothing to them!