is 2 56873 - 1
has 17121 decimal digits
takes 0.000 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual267522.460976.1194 %61000000079662357998223074,646.834230.8511 %75,169.295183.4868 %
Target2440.000063.6364 %500500000.00002.1165 %0.000064.4060 %
Difference+23+522.4608+12.4830 %+609999500+796623579932230+74,646.8342+28.7345%+75,169.2951+19.0808 %

Known prime factors (1 factor, 47.8 bits, 0.08397437% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
568732381304407790791547.7592093528043
32 × 37 × 89 × 70639
1999-08-3189706390.00036.764e-61.236e-5

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2016-10-02kkmrkkblmbrbkManual testing100000000200000000012
skipped known factor: 238130440779079
---39.731%
2023-04-24JacobZGreatLakes610000000796623579982230
skipped known factor: 238130440779079
--117,12771.010%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-05-04ATHcolab-Pp215000000150000000027--0.176


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1999-08-31ANONYMOUSv4_computers??47.75915


ECM factoring results:
Total ECM effort:93.925 GHz-days
Estimated T-Level:32.871
DigitsB1CompleteFacMiss
2011000174.1560.000%
255000033.2230.000%
302500004.8130.813%
3510000000.57456.321%
4030000000.05794.416%
45110000000.00599.509%


ECM Summary

B1B2factorcurvesGHz-days
5000050000002810.327
250000250000005853.619
100000010000000042712.00
1000000175391580010.158
10000002054008110509.102
177856591891049254433.86
204748636429445885016.37
233648341080601105018.49


Lucas-Lehmer results:
No L-L results for M56873


PRP results:
dateuseridcompidcofactorsres64
2017-09-21Oliver KruseOliver-PC
238130440779079
1B81DE6BB2AF98E4
2017-09-21Oliver KruseManual testing
238130440779079
1B81DE6BB2AF98E4
2017-10-13kkmrkkblmbrbkManual testing
238130440779079
1B81DE6BB2AF98E4
2020-04-17Oliver KruseAddPrpType5
238130440779079
21696CC71733EB7B


CERT results:
No CERT results for M56873


P-1 factor-bounds graph:
B1 = 610000000, B2 = 796623579982230 (P-1 stage 2)
B1 = 610000000 (P-1 stage 1)
B1 = 100000000, B2 = 2000000000 (P-1 stage 2)
B1 = 100000000 (P-1 stage 1)
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TF factor-bounds graph:
this exponent TF target: 44
TF double-checked to: 67
ECM T-Level=32.87 ~= 93-bit
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Last modified: 2024-02-18T12:01:28+00:00