Hard to tell without viewing the comp, but from your screenshot, I'd assume the 1 is it's own, separate layer. If it isn't and AE is unable to cope with arabic characters, it might be easier to manually align it.
You can add a shape layer to the position where you would like to center to... then parent whatever layer (inyour your case your text) to that shape whilst holding down "Shift" on your keyboard. It will snap it into place and then just unparent it and delete that unneeded shape layer. Hope that can helps you.