Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 230: | \[{21^{230}-1\over20}\] | 2 × 5 × 11 × 47 × 277 × 461 × 599 × 691 × 1381 × 2531 × 11731 × 19597 × 40841 × 185641 × 22952851 × 595377311 × 688660481 × 58286351831<11> × 69727564981<11> × 282924347471791<15> × 2215825387044753577<19> × 139870566115103282847737<24> × 3394964812534556016503466037951<31> × 209058863218345220988748673221343512407060674263723023401269471<63> × 162708209139159956445385758966200454982244714891163955510792310084461<69> |