2 161 Exponent Status

PrimeNet Exponent Status

M_n

Details

Composite, with 4 known prime factors. Cofactor is composite.

Trial Factored to 2⁶⁸

TF target 2⁴⁴

Factored

Factor	Digits	Bits	Date
117194366114889271070074059667667222873	39	126.5	old
30553899007233789447243614436947582588570307358207	50	164.4	2012-06-08 22:22:04
27167810694858396626049120029408370362093326314946087279160569	62	204.1	2020-09-04 02:28:51
56486824832476092597936178673369952799696200730531645364799743	62	205.1	2012-04-12 12:13:55

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	60978 / 105362

Estimated T-Level: 57.9 ⓘ

TF below 2^187 is very unlikely to find new factors due to ECM effort.

PRP Cofactor

Status	Proof	Date	User	Residue	Number of known factors	Shift	Type	Base
Factored	No proof (small exponent)	2017-09-21	Oliver Kruse	0927E1C3D6A0AC8F	3	0	1	3
Factored	No proof (small exponent)	2017-10-02	kkmrkkblmbrbk	0927E1C3D6A0AC8F	3	0	1	3
Factored	No proof (small exponent)	2017-12-07	ATH	0927E1C3D6A0AC8F	3	745	1	3
Factored	No proof (small exponent)	2020-04-17	Oliver Kruse	1F9F7E4CB26E247B	3	1100	5	3
Verified	No proof (small exponent)	2020-09-04	atrench	1F9F7E4CB26E247B	4	1475	5	3

History

Date	User	Type	Result
2025-09-30	Gerry Snyder	NF-PM1	B1=10000000, B2=27417655285020
2025-09-24	Gerry Snyder	F-ECM	Factor: 117194366114889271070074059667667222873 / ECM curve 20, B1=1000000000, B2=109343082518670, Edwards Sigma=4019054821601404
2025-09-23	Gerry Snyder	F-ECM	Factor: 117194366114889271070074059667667222873 / ECM curve 2, B1=1000000000, B2=67288049288460, Edwards Sigma=2837574767540265
2025-04-02	masser	NF-PP1	Start=108/29, B1=5300000000, B2=5294700000000
2024-05-15	masser	NF-PM1	B1=100000000000, B2=139738497657759000
2020-09-04	atrench	C-PRP	M2161/117194366114889271070074059667667222873/30553899007233789447243614436947582588570307358207/27167810694858396626049120029408370362093326314946087279160569/56486824832476092597936178673369952799696200730531645364799743 : 1F9F7E4CB26E247B
2020-09-04	Ryan Propper	F-ECM	Factor: 27167810694858396626049120029408370362093326314946087279160569
2020-04-17	Oliver Kruse	C-PRP	M2161/117194366114889271070074059667667222873/30553899007233789447243614436947582588570307358207/56486824832476092597936178673369952799696200730531645364799743 : 1F9F7E4CB26E247B
2017-12-07	ATH	C-PRP	M2161/117194366114889271070074059667667222873/30553899007233789447243614436947582588570307358207/56486824832476092597936178673369952799696200730531645364799743 : 0927E1C3D6A0AC8F
2017-10-02	kkmrkkblmbrbk	C-PRP	M2161/117194366114889271070074059667667222873/30553899007233789447243614436947582588570307358207/56486824832476092597936178673369952799696200730531645364799743 : 0927E1C3D6A0AC8F
2017-09-21	Oliver Kruse	C-PRP	M2161/known_factors : 0927E1C3D6A0AC8F
2016-09-08	kkmrkkblmbrbk	NF-PM1	B1=10000000000, B2=500000000000, E=12
2012-06-08	Michael Kenn	F-ECM	Factor: 30553899007233789447243614436947582588570307358207
2012-04-12	Michael Kenn	F-ECM	Factor: 56486824832476092597936178673369952799696200730531645364799743
2009-05-17	-anonymous-	F-PM1	Factor: 117194366114889271070074059667667222873
2002-07-27	Gerry Snyder	F-PM1	Factor: 117194366114889271070074059667667222873
2002-05-25	-anonymous-	NF-PM1	B1=1073741824, B2=4290000000
2001-05-27	-anonymous-	NF-PM1	B1=3000000000, B2=4290000000
2001-02-11	-anonymous-	NF-PM1	B1=1000000, B2=100000000
2000-07-25	-anonymous-	NF	no factor TF: 1-56
2000-01-25	-anonymous-	NF	no factor TF: 54-55

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