2 161 Exponent Status

Great Internet Mersenne Prime Search
GIMPS
Finding World Record Primes Since 1996

PrimeNet Exponent Status

M_n

Status

Details

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

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.

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified (Factored)	2017-09-21	Oliver Kruse	0927E1C3D6A0AC8F	3	0	1	3
Verified (Factored)	2017-10-02	kkmrkkblmbrbk	0927E1C3D6A0AC8F	3	0	1	3
Verified (Factored)	2017-12-07	ATH	0927E1C3D6A0AC8F	3	745	1	3
Verified (Factored)	2020-04-17	Oliver Kruse	1F9F7E4CB26E247B	3	1100	5	3
Verified	2020-09-04	atrench	1F9F7E4CB26E247B	4	1475	5	3

Assigned

Assigned	User	Work Type	Stage	% Done	Updated	Expired
2025-09-22	Gerry Snyder	factor ECM small		0.00 %	2025-09-24
2025-09-20	Gerry Snyder	factor ECM small		0.00 %	2025-09-23

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 PRP: Verified PRP without proof (small exponent)
2020-09-04	Ryan Propper	F-ECM	Factor: 27167810694858396626049120029408370362093326314946087279160569 / (ECM curve 1, B1=850000000, B2=15892628251516, Sigma=10531295418658479265)
2020-04-17	Oliver Kruse	C-PRP	M2161/117194366114889271070074059667667222873/30553899007233789447243614436947582588570307358207/56486824832476092597936178673369952799696200730531645364799743 : 1F9F7E4CB26E247B PRP: Verified PRP without proof (small exponent)
2017-12-07	ATH	C-PRP	M2161/117194366114889271070074059667667222873/30553899007233789447243614436947582588570307358207/56486824832476092597936178673369952799696200730531645364799743 : 0927E1C3D6A0AC8F PRP: Verified PRP without proof (small exponent)
2017-10-02	kkmrkkblmbrbk	C-PRP	M2161/117194366114889271070074059667667222873/30553899007233789447243614436947582588570307358207/56486824832476092597936178673369952799696200730531645364799743 : 0927E1C3D6A0AC8F PRP: Verified PRP without proof (not generated)
2017-09-21	Oliver Kruse	C-PRP	M2161/known_factors : 0927E1C3D6A0AC8F PRP without proof (not generated)
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