12 491 Exponent Status

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

PrimeNet Exponent Status

M_n

Details

Composite, with 3 known prime factors. Cofactor is composite.

Trial Factored to 2⁶⁸

TF target 2⁴⁴

Factored

Factor	Digits	Bits	Date
26006263	8	24.6	old
176240015761	12	37.4	2008-08-26 19:58:37
2498294556871	13	41.2	2008-08-26 19:58:37

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	640 / 640
35	1000000	1566 / 1566
40	3000000	4588 / 4588
45	11000000	3667 / 9201

Estimated T-Level: 42.0 ⓘ

TF below 2^134 is very unlikely to find new factors due to ECM effort.

Status	Proof	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	No proof (small exponent)	2017-09-21	Oliver Kruse	B95671F4D9BD69C9	3	0	1	3
Verified	No proof (small exponent)	2017-10-12	kkmrkkblmbrbk	B95671F4D9BD69C9	3	6104	1	3
Verified	No proof (small exponent)	2020-04-17	Oliver Kruse	891FFF22BD5BF0C3	3	11460	5	3
Verified	No proof (small exponent)	2024-07-01	kkmrkkblmbrbk	891FFF22BD5BF0C3	3	3654	5	3

History

Date	User	Type	Result
2025-03-04	masser	NF-PP1	Start=160/23, B1=430000000, B2=429570000000
2025-02-22	masser	NF-PP1	Start=6/5, B1=430000000, B2=429570000000
2025-01-19	masser	NF-PP1	Start=2/7, B1=430000000, B2=429570000000
2024-09-25	-anonymous-	NF-PM1	B1=1000000000000, B2=1403084906657654220
2024-07-01	kkmrkkblmbrbk	C-PRP	M12491/176240015761/2498294556871/26006263 : 891FFF22BD5BF0C3
2022-09-11	BloodIce	NF-PM1	B1=100000000000, B2=65542071839964720
2022-08-29	BloodIce	NF-PM1	B1=10000000000, B2=4099880487682980
2022-08-28	BloodIce	NF-PM1	B1=1000000000, B2=333483097867920
2022-08-28	BloodIce	NF-PM1	B1=100000000, B2=28207674615120
2020-04-17	Oliver Kruse	C-PRP	M12491/26006263/176240015761/2498294556871 : 891FFF22BD5BF0C3
2017-10-12	kkmrkkblmbrbk	C-PRP	M12491/26006263/176240015761/2498294556871 : B95671F4D9BD69C9
2017-09-21	Oliver Kruse	C-PRP	M12491/26006263/176240015761/2498294556871 : B95671F4D9BD69C9
2017-09-21	Oliver Kruse	C-PRP	M12491/26006263/176240015761/2498294556871 : B95671F4D9BD69C9
2016-09-09	kkmrkkblmbrbk	NF-PM1	B1=100000000, B2=10000000000, E=12
2008-08-26	-anonymous-	F	Factor: 2498294556871
2008-08-26	-anonymous-	F	Factor: 176240015761