Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 292: | \[{21^{292}-1\over20}\] | 22 × 11 × 13 × 17 × 293 × 439 × 877 × 1607 × 20149 × 30661 × 8303167 × 21483317 × 6899178178539541<16> × 9428689079641451<16> × 1405941375841813597<19> × 1427364308750988577<19> × 11133979244859457087136933<26> × 291735354693567319588543905901<30> × 7464630301668237280651468212188413809960173<43> × 1835844463335946645899043268633231545679549380228941168667759174055978247725171002215805897<91> × 5424905842809814580790135175148153005273370039115139875248165723989059011789226683837426053<91> |