is 2 2827553 - 1
has 851179 decimal digits
takes 0.218 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LC304EF20EF8337E8double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26821.080067.6471%50000002000000001.74989.1667%22.829870.6128%2.9657%
PrimeNet2590.027262.7119%120002400000.00272.9323%0.029963.8053%1.0934%
GPU722630.564565.0794%160002600000.00331.8262%0.567765.7171%0.6377%
Difference+5+20.5156+2.5677%+4984000+199740000+1.7465+7.3405%+22.2621+4.8957%+4.8957%

Known prime factors (1 factor, 69.4 bits, 0.00245498% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
28275537874541558789494507692169.416139246577496328
23 × 17405822187041
2020-09-1381740582218704143.577106,204198,360

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-28T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.243%
2016-09-19T01:31:06Jocelyn Larouchelow 4M12000033000006---0.033--2.866%
2016-09-21T12:09:20Jocelyn Larouchelow 4M1200003630000---0.035--2.927%
2016-09-22T12:02:47Jocelyn Larouchelow 4M1200003993000---0.037--2.987%
2016-12-24T02:28:32Jocelyn Larouchelow 4M207360207360---0.023--1.255%
2017-02-25T21:08:07Jocelyn Larouchelow 4M29859829859806---0.050--3.228%
2017-10-07T21:35:20Jocelyn Larouchelow 4M59719659719606---0.100--4.096%
2019-11-10T16:24:54masserManual testing30000003000000012---0.501--6.483%
2020-01-24T15:13:23masserManual testing500000020000000012---1.750--9.167%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:22Mark RoseManual testing21260--0.054--
2009-02-13T15:00:00Sturle Sundegigi.ifi260261--0.054--
2012-02-15T10:38:00markroldgamer261262--0.109--
2013-01-10T10:21:00dbaughManual testing262263--0.347--
2015-04-21T09:19:00VictordeHollanderManual testing263264--0.694--
2015-04-21T09:19:00VictordeHollanderManual testing264265--1.321--
2016-02-13T14:46:55ramgeisManual testing265266--2.643--
2017-10-28T16:39:39Gordon SpenceManual testing266267--5.286--
2019-01-03T01:11:02chuenkitManual testing267268--10.57--


ECM factoring results:

Old Calculation Method

Total ECM effort:3.548 GHz-days
Estimated T-Level:1.700
DigitsB1CurvesCompleteFacMiss
201100034 / 1000.34071.055%
255000034 / 2800.12188.546%

New Calculation Method

Total ECM effort:3.548 GHz-days
Estimated T-Level:1.700
DigitsB1CompleteFacMiss
20110001.30827.044%
25500000.12188.604%
302500000.00899.240%


ECM Summary

B1B2factorcurvesGHz-days
500005000000303.130
50000500000040.417


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-23T00:00:00ANONYMOUSv4_computersC304EF20EF8337E80.218
2018-09-09T05:26:56kkmrkkblmbrbkoldC304EF20EF8337E80.218


PRP results:
dateuseridcompidcofactorsres64PRP
2020-09-13T16:34:12bald2718281828splint1
787454155878949450769
1179F6527B34D644no
2020-09-14T21:59:45oodairacom1
787454155878949450769
1179F6527B34D644no


P-1 factor-bounds graph:
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 3000000, B2 = 30000000 (P-1 stage 2)
B1 = 3000000 (P-1 stage 1)
B1 = 597196, B2 = 5971960 (P-1 stage 2)
B1 = 597196 (P-1 stage 1)
B1 = 298598, B2 = 2985980 (P-1 stage 2)
B1 = 120000, B2 = 3993000 (P-1 stage 2)
B1 = 120000, B2 = 3630000 (P-1 stage 2)
B1 = 298598 (P-1 stage 1)
B1 = 120000, B2 = 3300000 (P-1 stage 2)
B1 = 207360 (P-1 stage 1)
B1 = 120000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2020-09-14T21:59:45+00:00