12 391 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
198257	6	17.6	old
54049543	8	25.7	2008-08-26 19:58:36
1260363922749217589025427951823	31	100.0	2009-07-10 05:47:49

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	640 / 640
35	1000000	1566 / 1566
40	3000000	4588 / 4588
45	11000000	1447 / 9201

Estimated T-Level: 40.8 ⓘ

TF below 2^130 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	EA18A7FEF03C887D	3	0	1	3
Verified	No proof (small exponent)	2017-10-02	kkmrkkblmbrbk	EA18A7FEF03C887D	3	0	1	3
Verified	No proof (small exponent)	2017-12-07	ATH	EA18A7FEF03C887D	3	854	1	3
Verified	No proof (small exponent)	2020-04-17	Oliver Kruse	97A4BB84D5BC79DC	3	1283	5	3
Verified	No proof (small exponent)	2024-07-01	kkmrkkblmbrbk	97A4BB84D5BC79DC	3	7113	5	3

History

Date	User	Type	Result
2025-03-05	masser	NF-PP1	Start=159/61, B1=430000000, B2=429570000000
2025-02-20	masser	NF-PP1	Start=6/5, B1=430000000, B2=429570000000
2025-01-19	masser	NF-PP1	Start=2/7, B1=430000000, B2=429570000000
2024-07-01	kkmrkkblmbrbk	C-PRP	M12391/1260363922749217589025427951823/198257/54049543 : 97A4BB84D5BC79DC
2023-05-13	-anonymous-	NF-PM1	B1=100000000000, B2=120417199046794650
2020-04-17	Oliver Kruse	C-PRP	M12391/198257/54049543/1260363922749217589025427951823 : 97A4BB84D5BC79DC
2017-12-07	ATH	C-PRP	M12391/198257/54049543/1260363922749217589025427951823 : EA18A7FEF03C887D
2017-10-02	kkmrkkblmbrbk	C-PRP	M12391/198257/54049543/1260363922749217589025427951823 : EA18A7FEF03C887D
2017-09-21	Oliver Kruse	C-PRP	M12391/198257/54049543/1260363922749217589025427951823 : EA18A7FEF03C887D
2017-09-21	Oliver Kruse	C-PRP	M12391/198257/54049543/1260363922749217589025427951823 : EA18A7FEF03C887D
2016-09-09	kkmrkkblmbrbk	NF-PM1	B1=100000000, B2=10000000000, E=12
2009-07-10	Rob_Dee	F-ECM	Factor: 1260363922749217589025427951823
2008-08-26	-anonymous-	F	Factor: 54049543