Base 31 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 128: | \[{31^{128}-1\over30}\] | 211 × 13 × 17 × 37 × 257 × 409 × 641 × 1129 × 1889 × 2689 × 4801 × 9601 × 1347329 × 6139297 × 23277313 × 13768516609<11> × 25085030513<11> × 17777097601059636481<20> × 7231746495781123585793<22> × 18596395822328738537384956455041<32> × 55107727353928381036964167246494350909954881<44> |