Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 422: | \[2^{422}-1\] | 3 × 4643 × 15193 × 9878177 × 5344743097<10> × 199061567251<12> × 60272956433838849161<20> × 22481127512575175864234185190299<32> × 3593875704495823757388199894268773153439<40> |