How Big is 64 Bit?

What is the term for how much space a 64 Bit Processor can address?

11 Bit = 1024K = Kilobyte
21 Bit = 1,048,576 = Megabyte
31 BIt = 1,073,741,824 = Gigabyte
40 Bit = 1,099,511,627,776 = Terrabyte
51 Bit = 1,125,899,906,842,620 = Petabytes
61 Bit = 1,152,921,504,606,850,000 = ??????

Max 64 Bit addressable space = 18,446,744,073,709,600,000

Any Help?