12 157 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
3209449	7	21.6	old
40239671	8	25.3	2008-08-26 19:58:36
7421846141404577273	19	62.7	2008-08-26 19:58:36

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	640 / 640
35	1000000	1566 / 1566
40	3000000	4588 / 4588
45	11000000	1603 / 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	40E4D056DC97288A	3	0	1	3
Verified	No proof (small exponent)	2017-10-12	kkmrkkblmbrbk	40E4D056DC97288A	3	12044	1	3
Verified	No proof (small exponent)	2020-04-17	Oliver Kruse	70D730B6FCF815B2	3	4878	5	3
Verified	No proof (small exponent)	2023-05-19	-anonymous-	70D730B6FCF815B2	3	7798	5	3

History

Date	User	Type	Result
2025-03-07	masser	NF-PP1	Start=172/29, B1=430000000, B2=429570000000
2025-02-26	masser	NF-PP1	Start=6/5, B1=430000000, B2=429570000000
2025-01-20	masser	NF-PP1	Start=2/7, B1=430000000, B2=429570000000
2023-05-19	-anonymous-	C-PRP	M12157/3209449/40239671/7421846141404577273 : 70D730B6FCF815B2
2023-04-06	-anonymous-	NF-PM1	B1=100000000000, B2=124652215247990430
2020-04-17	Oliver Kruse	C-PRP	M12157/3209449/40239671/7421846141404577273 : 70D730B6FCF815B2
2017-10-12	kkmrkkblmbrbk	C-PRP	M12157/3209449/40239671/7421846141404577273 : 40E4D056DC97288A
2017-09-21	Oliver Kruse	C-PRP	M12157/3209449/40239671/7421846141404577273 : 40E4D056DC97288A
2017-09-21	Oliver Kruse	C-PRP	M12157/3209449/40239671/7421846141404577273 : 40E4D056DC97288A
2016-09-08	kkmrkkblmbrbk	NF-PM1	B1=100000000, B2=10000000000, E=12
2008-08-26	-anonymous-	F-ECM	Factor: 7421846141404577273
2008-08-26	-anonymous-	F	Factor: 40239671