There are n cubes of the same size, and they are stacked into a cuboid, and the bottom of the cuboid is the bottom of the original cube. If the surface area of this cuboid is 3096 cm2, and when a cube is removed from the top of the cuboid, the surface area of the new cuboid is 144 cm2 less than that of the original cuboid, what is n? (Write a brief answer steps)
有n个同样大小的正方体，将它们摞成一个长方体，这个长方体的底面就是原正方体的底面．如果这个长方体的表面积是3096平方厘米，当从这个长方体的顶部拿去一个正方体后，新的长方体的表面积比原来长方体的表面积减少144平方厘米，那么n是多少？(写出简要解答步骤)
<result>21</result>