Base 28 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 85: | \[{28^{85}-1\over27}\] | 637421 × 887401 × 148020807352107352204781<24> × 451024205517517423233774595442089125772950234281803785388700007290734071220905548590621<87> |