Base 13 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
72: | \[{13^{72}-1\over12}\] | 23 × 32 × 5 × 7 × 17 × 19 × 37 × 61 × 73 × 157 × 271 × 937 × 4177 × 14281 × 28393 × 181297 × 428041 × 1471069 × 1609669 × 815702161 × 9818892432332713<16> |