Base 28 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
65: | \[{28^{65}-1\over27}\] | 53 × 131 × 637421 × 72416371 × 4543753614603737<16> × 90216355836698261<17> × 3276407634171096216610291054196844397042681<43> |