| k | Digits | Early discovery with at least 100,000 digits | Who | When | 1 | 227832 | 2756839 − 1 | David Slowinski & Paul Gage | 19 Feb 1992 |
| 2 | 100355 | 65516468355 • 2333333 ± 1 | Peter Kaiser, PrimeGrid | 15 Aug 2009 |
| k | Digits | Early discovery with at least 200,000 digits | Who | When |
| 1 | 227832 | 2756839 − 1 | David Slowinski & Paul Gage | 19 Feb 1992 |
| 2 | 200700 | 3756801695685 • 2666669 ± 1 | Timothy Winslow, PrimeGrid | Dec 2011 |
| k | Digits | Early discovery with at least 300,000 digits | Who | When |
| 1 | 378632 | 21257787 − 1 | David Slowinski & Paul Gage | 3 Sep 1996 |
| 2 | 388342 | 2996863034895 • 21290000 ± 1 | Tom Greer, PrimeGrid | 19 Sep 2016 |
| k | Digits | Early discovery with at least 1,000,000 digits | Who | When |
| 1 | 2098960 | 26972593 − 1 | Nayan Hajratwala, GIMPS | 1 Jun 1999 |
| k | Digits | Early discovery with at least 10,000,000 digits | Who | When |
| 1 | 12978189 | 243112609 − 1 | Edson Smith, GIMPS | 23 Aug 2008 |
| k | Digits | Early discovery with at least 20,000,000 digits | Who | When |
| 1 | 22338618 | 274207281 − 1 | Curtis Cooper, GIMPS | 7 Jan 2016 |