Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 821: | \[2^{821}-1\] | 419273207 × 109840721427977<15> × 286121480219517473<18> × 25348330589061322436059499894718930577798031880081867566547223<62> × 41866449065688547732334670918138300495432254381696818748989283844419920572286356810694501570678523880104345359476534651949605873238987445628114071<146> |