Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
192: | \[2^{192}-1\] | 32 × 5 × 7 × 13 × 17 × 97 × 193 × 241 × 257 × 641 × 673 × 65537 × 6700417 × 22253377 × 18446744069414584321<20> |