Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 198: | \[{21^{198}-1\over20}\] | 2 × 112 × 19 × 23 × 37 × 67 × 199 × 421 × 463 × 613 × 3499 × 6073 × 28513 × 33199 × 1130581 × 10362529 × 85775383 × 17513875027111<14> × 87989435079877<14> × 782006960636353<15> × 146354764854514987<18> × 3955202198062795629622003<25> × 188145268678304791443009491673532813732054627291<48> × 19050347137684245501074582624627605674546940303323636856235442615869112421<74> |