Base 28 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 52: | \[{28^{52}-1\over27}\] | 5 × 29 × 53 × 157 × 547 × 2237 × 114661 × 1598039 × 78296083533149<14> × 4543753614603737<16> × 687858517721621226917<21> |