Base 11 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
81: | \[{11^{81}-1\over10}\] | 7 × 19 × 1772893 × 139026457 × 5559917315850179173<19> × 14010692617072784593<20> × 88236431987113771637099217013<29> |