Largest Known Prime Number discovered

[Gerson W. Barbosa]

(01-05-2018 01:24 PM)Don Shepherd Wrote:  My HP-65 can find that number in ..... well, I take that back!

My HP-50g can evaluate M4253 (2^4253 - 1) in less than 30 seconds, but that one was discovered in November 1961.

4253

« 1 DUP ROT
START DUP +
NEXT 1 -
»

EVAL

->

19079700752443907380746804296952917366935699474994017739474188267352897978700505​37063680498355149002443034959549507097257621863112241488288119202169045422069607​44666169364221195289538436845390250168663932838805192055137154390912666527533007​30929268753909225704336251785736662469997540237546295449029325923330313733064353​15565397399219262014386064390200751747230290568382725050515719675946083500634044​95977660656269020823960825567012344189908927956646011998057988548630107637380993​51982658238978188813570540865304521965580175808125116408055460905746802820330871​87246540810553232158601896113912960304711084431467456719677663089258585472715073​11563765171008318248647110097614890313562856541784154881743146033909602737947385​05535596033185561454090008145637865906837031726769698000118775099549109035010841​70509179915621679722810701613059725180448720483313063837150948549384157385498946​06070722584737978176686422134354526989443028353644037187375385397838259511833166​41613432369566036767689772228791877342096898232608902615003151542416546211133752​74311548906663273749214462768335645197767976338755035486650939145564820314822488​83127023777039667707976559857333357013727342079099064400455741830654320379350833​23624581934882406478358569292488102197833297494990612266442137603468781535048499​1

PS: M23209, discovered in 1979, takes about 333 seconds (6987 digits long).