If you have the kit lens it is a variable aperture lens meaning its max aperture at 18mm is f3.5 and at 55mm it is f5.6 so that means the lens at 18mm is max f3.5 to min f22 and at 55mm it is max f5.6 to min f22. Being that its max aperture is variable its max aperture at lets say 35mm maybe f4.5 to f22. Nikon and most stores list the max apertures for the shortest and longest focal length but not the minimum aperture. Just a marketing tool I think.
Here's a link to Nikon USA's sire with its spec's listed.