Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 150: | \[{21^{150}-1\over20}\] | 2 × 52 × 11 × 31 × 101 × 151 × 211 × 421 × 463 × 1051 × 1801 × 2551 × 9391 × 18181 × 40841 × 185641 × 386851 × 501001 × 2031851 × 11093851 × 263977951 × 9728219701<10> × 201307465501<12> × 895322420811001<15> × 248303068144516751<18> × 27385718497004633851<20> × 138288178346489520230701<24> × 846605446315436611973101<24> |