12 239 Exponent Status

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

PrimeNet Exponent Status

M_n

Details

Composite, with 2 known prime factors. Cofactor is composite.

Trial Factored to 2⁶⁸

TF target 2⁴⁴

Factored

Factor	Digits	Bits	Date
288373592888473	15	48.0	old
248344365828022895426978263	27	87.7	2008-08-29 02:24:29

P-1 factors

Date	Factors	B1	B2
2023-04-06	No new factors discovered	100000000000	121982729876067056

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	640 / 640
35	1000000	1566 / 1566
40	3000000	4588 / 4588
45	11000000	1613 / 9201

Estimated T-Level: 40.9 ⓘ

TF below 2^131 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	6C2A4C0529A64195	2	0	1	3
Verified	No proof (small exponent)	2017-10-02	kkmrkkblmbrbk	6C2A4C0529A64195	2	0	1	3
Verified	No proof (small exponent)	2017-12-07	ATH	6C2A4C0529A64195	2	12190	1	3
Verified	No proof (small exponent)	2020-04-17	Oliver Kruse	6168112C5E3396EB	2	4994	5	3
Verified	No proof (small exponent)	2024-07-01	kkmrkkblmbrbk	6168112C5E3396EB	2	3345	5	3

History

Date	User	Type	Result
2025-03-07	masser	NF-PP1	Start=92/53, B1=430000000, B2=429570000000
2025-02-24	masser	NF-PP1	Start=6/5, B1=430000000, B2=429570000000
2025-01-20	masser	NF-PP1	Start=2/7, B1=430000000, B2=429570000000
2024-07-01	kkmrkkblmbrbk	C-PRP	M12239/248344365828022895426978263/288373592888473 : 6168112C5E3396EB
2023-04-06	-anonymous-	F-PM1	Factor: 248344365828022895426978263 / B1=100000000000, B2=121982729876067060
2020-04-17	Oliver Kruse	C-PRP	M12239/288373592888473/248344365828022895426978263 : 6168112C5E3396EB
2017-12-07	ATH	C-PRP	M12239/288373592888473/248344365828022895426978263 : 6C2A4C0529A64195
2017-10-02	kkmrkkblmbrbk	C-PRP	M12239/288373592888473/248344365828022895426978263 : 6C2A4C0529A64195
2017-09-21	Oliver Kruse	C-PRP	M12239/288373592888473/248344365828022895426978263 : 6C2A4C0529A64195
2017-09-21	Oliver Kruse	C-PRP	M12239/288373592888473/248344365828022895426978263 : 6C2A4C0529A64195
2016-09-09	kkmrkkblmbrbk	NF-PM1	B1=100000000, B2=10000000000, E=12
2008-08-29	-anonymous-	F-ECM	Factor: 248344365828022895426978263