Base 28 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 78: | \[{28^{78}-1\over27}\] | 3 × 29 × 53 × 79 × 271 × 547 × 757 × 1483 × 1951 × 2237 × 114661 × 284467 × 1598039 × 219386077 × 4543753614603737<16> × 81923931656777716741<20> × 2485157691702736928051924257<28> |