Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 258: | \[{21^{258}-1\over20}\] | 2 × 11 × 173 × 421 × 463 × 1033 × 15739 × 18061 × 126851 × 203563 × 1135201 × 169367548429<12> × 1163308526467<13> × 478811691676843729951<21> × 865024042330045810749522301<27> × 575249475635243150387227010911<30> × 7953436401867987800552310336799<31> × 667194113877071063826883433793238376554018717<45> × 35842614220783025524408588074144786493150233831596714503<56> × 119000957796440462394517307940919912228603619382831962610320796808847023<72> |