Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 235: | \[{21^{235}-1\over20}\] | 5 × 941 × 34781 × 40841 × 49727 × 227011 × 75042551 × 158545759 × 5298873343<10> × 8254573388881<13> × 9794718038248648833094153<25> × 6847542200417623658286640749840415955091782235483838756785987494581852814202162065111680127421360589450531118883189885048745738874371691308843719040047907624465328369267229327176507948728332834799714106958677428458294440041<223> |