Ubasic

Here I would like to link to a site that has many programs involved with number theory, but notably Ubasic, a program that, among other assets, allows calculation with numbers up to 2600 digits. The .ZIP package also includes a help file that will help even a beginning programer to write complex programs. Here is the link:

Or, to look at all the other great programs that they are giving away for free, go here:

Those are MSDOS programs, go here for Mac stuff:

Don't get lost! I did.