Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 122: | \[{20^{122}-1\over19}\] | 3 × 7 × 1831 × 1575631 × 74324733207911<14> × 12287385389923456825324271923<29> × 89361605071686412034862241221156703859155917764047<50> × 5659784747821331230431654824725808002385097133154909051<55> |