To calculate the volume of the rectangular prism, we need to know the dimensions of the prism. Since we are given that it is filled with 2,200 cubes and each cube has an edge length of 15 of an inch, we can determine that the total volume of all the cubes is:

2,200 cubes x (15/12)^3 cubic inches per cube = 2,200 cubes x 0.5781 cubic inches per cube = 1,278.125 cubic inches

Therefore, the volume of the rectangular prism is 1,278.125 cubic inches.