Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 44: | \[{21^{44}-1\over20}\] | 22 × 112 × 13 × 17 × 23 × 89 × 661 × 6073 × 10362529 × 17513875027111<14> × 4718573764413203147069<22> |