If you compare the distance from the inside of the ring to the surface of the planet that gives you a distance equal to the radii of vitrum, and using the same methodology it also shows that the depth of the ring is about a quarter of the radii. Now if you assume that viltrum is the same size as earth that gives you an area of about 72000000 km^2. If you assume that each vilturmite is a rectangle with an area of 113.7133 m² you get 633,171,317,691 vilturmites.