12 647 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
8599961	7	23.0	old
850485457	9	29.7	2008-08-26 19:58:37
21578667537698833	17	54.3	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	1463 / 9201

Estimated T-Level: 40.8 ⓘ

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	B9B6A59925043EA4	3	0	1	3
Verified	No proof (small exponent)	2017-10-12	kkmrkkblmbrbk	B9B6A59925043EA4	3	4932	1	3
Verified	No proof (small exponent)	2020-04-17	Oliver Kruse	ADEDAE10BFC98DB5	3	11231	5	3
Verified	No proof (small exponent)	2024-07-01	kkmrkkblmbrbk	ADEDAE10BFC98DB5	3	3378	5	3

History

Date	User	Type	Result
2025-03-12	masser	NF-PP1	Start=184/11, B1=430000000, B2=429570000000
2025-02-18	masser	NF-PP1	Start=6/5, B1=430000000, B2=429570000000
2025-01-17	masser	NF-PP1	Start=2/7, B1=430000000, B2=429570000000
2024-07-01	kkmrkkblmbrbk	C-PRP	M12647/21578667537698833/850485457/8599961 : ADEDAE10BFC98DB5
2023-05-13	Anton Repko	NF-PM1	B1=100000000000, B2=120417199046794650
2022-02-05	Joss	NF-PM1	B1=1000000, B2=3910366209750
2020-04-17	Oliver Kruse	C-PRP	M12647/8599961/850485457/21578667537698833 : ADEDAE10BFC98DB5
2017-10-12	kkmrkkblmbrbk	C-PRP	M12647/8599961/850485457/21578667537698833 : B9B6A59925043EA4
2017-09-21	Oliver Kruse	C-PRP	M12647/8599961/850485457/21578667537698833 : B9B6A59925043EA4
2017-09-21	Oliver Kruse	C-PRP	M12647/8599961/850485457/21578667537698833 : B9B6A59925043EA4
2008-08-26	-anonymous-	F-PM1	Factor: 21578667537698833
2008-08-26	-anonymous-	F	Factor: 850485457