Base 7 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 81: | \[{7^{81}-1\over6}\] | 34 × 19 × 37 × 109 × 811 × 1063 × 1621 × 2377 × 3727 × 2583253 × 3368791 × 70722308812401674174993533367023<32> |