Wincalc for Windows 95/98/ME/2K/XP/Vista (201K)
Click the above link to download the program. (21 Sep 08)
Page last updated: 30 Jun 09
Wincalc allows the user to calculate integers with millions of digits.
Some gigantic Mersenne primes have already been calculated for you. (30 Jun 09)
There are a few additional large strings of digits here. (2 Aug 06)
If the program behaves strangely, there is a page of FAQ, which may help. If not, you can e-mail me at the address found in the program’s Help|About dialog box.
Follow the links for more information about the Windows 95/98/ME/2K/XP/Vista version or the Windows 3.1 version.
30 Jun 09: Calculated and uploaded the 47rd Mersenne prime M42643801, to keep my library of examples up to date.
19 Nov 06: Discovered how to word-wrap my help texts. I await news of unintended consequences.
2 Aug 06: Taught the parser to ignore non-digits when pasting a numerical text in from the clipboard.
10 Jan 06: As expected, the 43rd Mersenne prime M30402457 took almost two days to calculate.
8 Jan 06: I was horrified to discover, as I began the long calculation of the recently announced 43rd Mersenne prime, that the last few million digits of my version of the 42nd Mersenne prime were incorrect! (It seems that I forgot that it is necessary to add back the 1 when converting a Mersenne prime back to a power of 2; I also forgot to check my work.) The current version of M25964951 has been recalculated and checked. I hope to have M30402457 ready in a couple of days.
28 Dec 05: In response to users reporting difficulty opening files by double-clicking file icons, new versions have been prepared that deal with file-naming conventions that allow spaces (and extra periods). See the FAQ.
2 Mar 05: The largest known Mersenne primes are now available for downloading as Wincalc files.
14 Feb 05: Saving a multi-page number as a text file is now done automatically, instead of requiring a page-by-page approach (which was a vestige of Windows 3.1 limitations).
31 Jan 05: Minor corrections: The text windows (help files, notebooks, tables, etc) were losing their carets (the blinking thing) now and then, and were not opening files correctly.
15 Jan 05: It seems that the old “search” function that I installed years ago in text windows no longer works under Windows XP, so I had to revise it.
11 Nov 04: The 40th Mersenne prime M20996011 is a 6320430-digit number. If you do not want to wait for Wincalc to calculate it (it takes many hours), you can download it as a Wincalc file here. The zipped file is about 2.79 megabytes.
23 Feb 04: At long last, I have finished a new version of Wincalc. I await suggestions and reports of bugs.
