base (b) largest known minimal prime written in base b largest known minimal prime written in decimal length of largest known minimal prime written in base b 2 11 3 2 3 111 13 3 4 221 41 3 5 1(0^93)13 5^95+8 96 6 40041 5209 5 7 (3^16)1 (7^17-5)/2 17 8 (4^220)7 (4*8^221+17)/7 221 9 3(0^1158)11 3*9^1160+10 1161 10 5(0^28)27 5*10^30+27 31 11 55(7^1011) (607*11^1011-7)/10 1013 12 4(0^39)77 4*12^41+91 42 13 8(0^32017)111 8*13^32020+183 32021 14 4(D^19698) 5*14^19698-1 19699 15 (7^155)97 (15^157+59)/2 157 16 D(B^32234) (206*16^32234-11)/15 32235 17 F7(0^186767)1 262*17^186768+1 186770 18 8(0^298)B 8*18^299+11 300 19 FG(6^110984) (904*19^110984-1)/3 110986 20 C(D^2449) (241*20^2449-13)/19 2450 21 C(F^479147)0K (51*21^479149-1243)/4 479150 22 K(0^760)EC1 22^763*20+7041 764 23 9(E^800873) (106*23^800873-7)/11 800874 24 2(0^313)7 2*24^314+7 315 25 9(6^136965)M (37*25^136966+63)/4 136967 26 (M^8772)P (22*26^8773+53)/25 8773 27 A(0^109003)PM 10*27^109005+697 109006 28 O4(O^94535)9 (6092*28^94536-143)/9 94538 29 O(0^174236)FPL 24*29^174239+13361 174240 30 O(T^34205) 25*30^34205-1 34206 31 IE(L^29787) (5727*31^29787-7)/10 29789 32 S(U^9748)L (898*32^9749-309)/31 9750 33 N7(0^610411)1 766*33^610412+1 610414 34 US(0^9374)R 1048*34^9375+27 9377 35 1B(0^56061)1 46*35^56062+1 56064 36 (P^81993)SZ (5*36^81995+821)/7 81995