Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 488: | \[{21^{488}-1\over20}\] | 23 × 11 × 13 × 17 × 367 × 2441 × 15373 × 75641 × 97241 × 2123777 × 12519763 × 262301953 × 6507039337<10> × 15569711981<11> × 939314334529<12> × 1128331159687<13> × 151583426311021<15> × 132538677158969693<18> × 1814065850324073713<19> × 37376752870606823789<20> × 732829221167645894129<21> × 9600772802405878717656259<25> × 57398774322642953389748085156004642469<38> × 131463780085166148358102805265075200384544766770894622886448240624433366398902783239941643349<93> × [820024784731642524530185098089744215958995763929795638384886882509211683658528127357225869189832282682326452358979203543461150943775220943434031104896368883899923746186981033730410482569423172173546155418150336204426024925598023423786900661599075199379273516675059733517258088971724234880885230917673187840417<309>] |