A while ago i built a program in Java that computed extreme factorials with absolute precision. Originally that was something to do to kill some time, but then I liked the project a lot so I continued on improving, changing and updating parts of it to make it faster and overall better.
It reached the point where Java's "BigInteger" is not big enough anymore to contain the numbers it is dealing with, so although it was able to calculate the factorial of 80,000,000 it was stuck at the final multiplication when calculating the factorial of 90,000,000 which was a pitty and calls for a re-write of BigInteger or a custom implementation of a huge number like that.
Note: There are more calculated factorials that are either too large in file size or too many to include here.
If you want a perticular factorial calculated drop me an email at
906049 (AT̹) swansea (DͦOT̤) ac (DͦOT̤) uk