Base 28 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 260: | \[{28^{260}-1\over27}\] | 52 × 11 × 29 × 53 × 61 × 131 × 157 × 547 × 2237 × 14561 × 53951 × 84961 × 114661 × 637421 × 1598039 × 72416371 × 115508406521<12> × 78296083533149<14> × 4543753614603737<16> × 90216355836698261<17> × 687858517721621226917<21> × 3276407634171096216610291054196844397042681<43> × 26074251673305922066983251816071456093808641348707301298501<59> × 8466903361711462061838607491167244309945854615631454386828550600756383160591065479920303160272374012326219201657225095358167278214395724561<139> |