This is a personal website.
Its aim is to find some factors of somewhat larger numbers,
which are taken from the database of Markus Tervooren
and where any result is uploaded to.
Finds in 2023: 6583 factors of 5752 numbers (Dec 28, 2023).
The largest factor is p42 = 713179443752745679211641547767533209753303 of 10^839 + 1.
(10^183917+1)/11/9952852373 is a probable prime with 183906 digits (February 9, 2024).
Finds in 2023: 2389 factors of 2305 numbers (Dec 28, 2023).
The largest factor is p55 = 2862577930401391395910619889316394633711512313018581507 of 10^1599 − 1.
For a large number it is not easy to determine wether it is prime or composite.
Marcel Martin wrote the program primo which can prove (or disprove) the primality of a number.
In a few cases I used it to create a certificate (Sep 30, 2024).
Lately I used the program cm (written by Andreas Enge) to create certificates.
Yet another collection of factors up to n < 1000000 with small but new own finds. Latest version Feb 11, 2025.
This section draws upon the definitions and explanations of Dario Alpern.
Searching for the maximal k-brilliant n-digit number (with k, n arbitrary but fixed) is my way to play this game.
Some finds so far. Latest version Mar 30, 2025.
Mar 31, 2025: 10^35 − 14972647671 = 307651 · 580733 · 839539 · 860369 · 864221 · 896633
Mar 30, 2025: 10^34 − 815987867 = 141863 · 333679 · 575669 · 588191 · 760927 · 819913
Mar 28, 2025: 10^31 − 8160991449 = 100333 · 131441 · 136069 · 147629 · 185557 · 203431
Mar 19, 2025: 10^44 − 254652041 = 13062611 · 17642657 · 22103087 · 22228883 · 22890377 · 38581801
March 31, 2025