43,252,003,274,489,856,000 combinations
----------------------------------------------------------
                                              
Long Version
Start with middle White square on top
Do middle pieces then do corner pieces
----------------------------------------------------------
Turn cube so the layer just done is at
the bottom,  i.e.  White layer

MIDDLE CORNERS
(URur)(ufUF) or (fuul)U(LUUF)

ORIENT UPPER EDGES
B(UL)(ul)b or B(LU)(lu)b

PUT UPPER EDGES IN PLACE
(LU)(lU)(LUU)l

PUT UPPER CORNERS IN PLACE
(URur)l(RUru)L

ORIENT UPPER CORNERS
(LU)(lU)(Luu)(l)
and (ru)(Ru)(ruu)(R)
--------------------------------------
Where:
U = Upper Clockwise
F = Front Clockwise
B = Back Clockwise
R = Right Clockwise
L = Left Clockwise
Lower case = Anticlockwise
Rubik's Cube