The V-Cube 7, invented by Panagiotis Verdes, is the 7x7x7 version of the Rubik's Cube. Like the 5x5x5 Professor's Cube, the V-Cube 7 has both fixed and movable center facets.
A V-Cube 7 consists of 218 unique miniature cubes, also called 'cubies': 8 corners, 60 edges, and 150 centers. The six centers are affixed to the core mechanism. The 7x7x7 cube has a total of 294 stickers.
The number of possible positions
The number of possible positions of the cube is 8! × 37 × 12! × 210 24!8 / 4!36 ≈ 1.950 × 10160 which is about 19.5 sexvigintillion or 19.5 sexvigintilliard on the long scale or 19.5 duoquinquagintillion on the short scale.
The diameter of the V-Cube 7
In July 18, 2011, Tomas Rokicki computed lower bounds for the N × N × N Rubik's Cubes using six different metrics. According to this, the 7x7x7 has a lower bound of 75 block turns. See also the article Lower Bounds for n x n x n Rubik's Cubes (through n=20) in Six Metrics for further informations.