Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 175: | \[{21^{175}-1\over20}\] | 52 × 43 × 631 × 1471 × 3319 × 40841 × 81901 × 2031851 × 4149601 × 20028751 × 24602533201<11> × 421503321597121<15> × 27385718497004633851<20> × 37686242599452410706868538086801<32> × 6107498812503060189977652663684219147254525910663051537427182386752756045066004222730822829713729595685422017301<112> |