is 2 1752721 - 1
has 527622 decimal digits
takes 0.095 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LC31FE037E07D8361double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26716.953068.6567%500000150000000.10155.0423%17.054570.2371%1.5804%
PrimeNet2570.011063.1579%80001400000.00122.8033%0.012164.1907%1.0328%
GPU722610.175365.5738%80001100000.00111.4131%0.176366.0603%0.4865%
Difference+6+16.7778+3.0829%+492000+14890000+0.1004+3.6292%+16.8782+4.1769%+4.1769%

Known prime factors (3 factors, 207.0 bits, 0.01180878% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
17527218773299681067817511859.606250276560875
53 × 11 × 37 × 4919441
-12549194410.07770.02110.0394
175272160519488743298591829112272.3581726443876215855
5 × 191 × 1807794634781
2020-07-201911807794634781585.207,747.814,471
1752721380747696909499357305692375.01110861617362646404
22 × 2715404340661601
2019-07-22427154043406616015,427.911,637,54421,735,692

4 Composite Factors:
exponentprime factorscomposite factordigitsbits*
1752721530955611289968907615123509198266585716140131.964
17527213340413647863416758062352038243962204631941134.617
175272123042655957151310395477068072079945418510635945147.369
175272120216012615983103671217161372385264016546573585579
6447135254609
63206.975
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2016-03-16T12:29:30alpertronManual testing5000001500000012-
skipped known factor: 877329968106781751
--0.101--5.042%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2003-01-25T00:00:00ANONYMOUSv4_computers21258--0.022--


ECM factoring results:

Old Calculation Method

Total ECM effort:17.667 GHz-days
Estimated T-Level:24.589
DigitsB1CurvesCompleteFacMiss
2011000257 / 1002.5707.555%
2550000257 / 2800.91839.872%

New Calculation Method

Total ECM effort:17.667 GHz-days
Estimated T-Level:24.589
DigitsB1CompleteFacMiss
20110008.2900.025%
25500000.74947.271%
302500000.04695.491%
3510000000.00299.789%


ECM Summary

B1B2factorcurvesGHz-days
50000500000025217.32
50000500000020.137
50000500000030.206


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-12-13T00:00:00Stephen Woodv4_computers024E18C7DAE9F9__0.095
1999-06-06T00:00:00Nayan Hajratwalav4_computersC31FE037E07D83610.095


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-03T07:09:40Oliver KruseGTX-1
877329968106781751
36053C2EE70780__no
2017-11-03T21:28:56kkmrkkblmbrbkc4.xlarge
877329968106781751
36053C2EE70780__no
2019-07-23T02:11:41Niels_Mache_NextcloudSuperDry-X
877329968106781751
38074769690949935730569
4FE85C01D57AD320no
2019-07-24T21:35:13arnaudstm-11-010
877329968106781751
38074769690949935730569
4FE85C01D57AD320no
2020-07-20T21:10:41CrypticClueManual testing
877329968106781751
6051948874329859182911
38074769690949935730569
4FE85C01D57AD320no


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2020-07-20T21:10:41+00:00