2 521 Exponent Status

PrimeNet Exponent Status

M_n

Details

Composite: proven not-prime with Lucas-Lehmer test

No factors below 2⁶⁶

TF target 2⁴⁴

P-1

B1 =	6000000000000
B2 =	9223372036854775807

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	640 / 640
35	1000000	1566 / 1566
40	3000000	4588 / 4588
45	11000000	9201 / 9201
50	44000000	16550 / 16550
55	110000000	40830 / 40830
60	260000000	105362 / 105362
65	800000000	194238 / 194238
70	2400000000	181151 / 350860

Estimated T-Level: 67.6 ⓘ

TF below 2^220 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Shift	Software
Verified		Unknown	59E9	0	Unknown,(aka U)
Verified		George Woltman	5FB1137F9314D9E9	0	Woltman,Prime95,first web release,(aka W4)
Verified		Brian J. Beesley	5FB1137F9314D9E9	0	Mac,John Sweeney,v1.4,(aka J3)
Verified	2015-04-11	MadPoo 🙂	5FB1137F9314D9E9	1066	Windows 64-bit,Prime95,v26,(aka We4)

History

Date	User	Type	Result
2025-07-11	ViliamF	NF-PP1	Start=6/5, B1=1000000000000
2025-06-25	ViliamF	NF-PP1	Start=2/7, B1=1000000000000
2024-10-18	-anonymous-	NF-PM1	B1=6000000000000, B2=1.4002737613484E+19
2023-08-10	masser	NF-PP1	Start=6/5, B1=3900000000, B2=698100000000
2023-07-03	masser	NF-PM1	B1=216000000000, B2=486755758363664790
2023-06-28	masser	NF-PP1	Start=76/29, B1=3900000000, B2=3896100000000
2022-05-04	Anton Repko	NF	no factor TF: 65-66
2021-05-13	ATH	NF-PP1	Start=2/7, B1=1000000000, B2=241000000000
2021-03-01	Anton Repko	NF	no factor TF: 64-65
2018-11-06	Joss	NF-PM1	B1=200000000000, B2=18000000000000, E=12
2018-11-05	Joss	NF-PM1	B1=200000000000, B2=15000000000000, E=12
2018-11-02	Joss	NF-PM1	B1=200000000000, B2=7000000000000, E=12
2018-11-01	Joss	NF-PM1	B1=200000000000, B2=4000000000000, E=12
2018-10-31	Joss	NF-PM1	B1=200000000000, B2=2000000000000, E=12
2018-01-25	snme2pm1	NF	no factor TF: 63-64
2016-11-19	snme2pm1	NF	no factor TF: 62-63
2016-02-23	LaurV	NF	no factor TF: 57-58
2015-06-28	snme2pm1	NF	no factor TF: 61-62
2015-06-22	trebor	NF-PM1	B1=100000000000, B2=10000000000000, E=12
2015-04-11	MadPoo 🙂	C-LL	5FB1137F9314D9E9
2012-05-22	bcp19	NF	no factor TF: 60-61
2010-12-04	monst	NF	no factor TF: 58-60
2010-02-16	James Hintz	NF-PM1	B1=50000000000, B2=1250000000000, E=12
2003-01-16	Alex Kruppa	NF	no factor TF: 1-57
2002-12-31	-anonymous-	NF-PM1	B1=4290000000
2002-12-25	Alex Kruppa	NF	no factor TF: 1-57
2002-12-25	-anonymous-	NF	no factor TF: 1-57
2002-09-14	-anonymous-	NF-PM1	B1=3221225472, B2=4290000000, E=48
2002-08-03	-anonymous-	NF-PM1	B1=2147483648, B2=4290000000, E=48
2001-06-03	-anonymous-	NF-PM1	B1=3000000000, B2=4290000000
2001-06-03	-anonymous-	NF-PM1	B1=43000000, B2=4290000000
2001-02-11	-anonymous-	NF-PM1	B1=1000000, B2=100000000
2000-08-10	-anonymous-	NF	no factor TF: 1-56
2000-02-01	-anonymous-	NF	no factor TF: 54-55
1999-12-15	-anonymous-	NF	no factor TF: 53-54
1999-09-22	-anonymous-	NF	no factor TF: 52-53
1999-09-14	-anonymous-	NF	no factor TF: 50-51

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