Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 609: | \[2^{609}-1\] | 72 × 127 × 233 × 337 × 1103 × 2089 × 4177 × 136417 × 121793911 × 9857737155463<13> × 11348055580883272011090856053175361113<38> × 15109165329245515231985834925494692879<38> × 16086815316499827472365485208334357981931315800699584898530365449<65> |