Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 174: | \[{21^{174}-1\over20}\] | 2 × 11 × 59 × 421 × 463 × 1277 × 5743 × 15661 × 729931 × 1103704099 × 246763300513<12> × 687613372491653<15> × 69250702723682869<17> × 7826081384442721874824416529<28> × 7865855595529911658005355038639053<34> × 25513656237116849236180811006302793510107213<44> × 13477015991023291802765110016390772920553907009<47> |