13 121 Exponent Status

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

PrimeNet Exponent Status

M_n

Details

Composite, with 4 known prime factors. Cofactor is composite.

Trial Factored to 2⁶⁸

TF target 2⁴⁴

Factored

Factor	Digits	Bits	Date
8883798075151	13	43.0	old
290310479097546074437362605040796310527	39	127.8	2021-09-13 20:13:44
838761350975792446742332334396224838945787119	45	149.2	2025-08-02 00:59:57
52666198803985699306925580112937986799538757577	47	155.2	2025-08-02 13:37:26

P-1 factors

Date	Factors	B1	B2
2023-10-10	No new factors discovered	100000000000	122154521813133808

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	640 / 640
35	1000000	1566 / 1566
40	3000000	4588 / 4588
45	11000000	1604 / 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
Factored	No proof (small exponent)	2017-09-21	Oliver Kruse	8CE135D75B37B59E	1	0	1	3
Factored	No proof (small exponent)	2017-10-12	kkmrkkblmbrbk	8CE135D75B37B59E	1	6804	1	3
Factored	No proof (small exponent)	2020-04-17	Oliver Kruse	88DD75E8482DCDAE	1	10072	5	3
Factored	No proof (small exponent)	2021-09-13	nordi	88DD75E8482DCDAE	2	9596	5	3
Factored	No proof (small exponent)	2021-09-13	SRJ2877	88DD75E8482DCDAE	2	4242	5	3
Verified	No proof (small exponent)	2025-09-03	Mingye Wang	88DD75E8482DCDAE	4	612	5	3

History

Date	User	Type	Result
2025-09-03	Mingye Wang	C-PRP	M13121/8883798075151/290310479097546074437362605040796310527/838761350975792446742332334396224838945787119/52666198803985699306925580112937986799538757577 : 88DD75E8482DCDAE
2025-08-02	Ryan Propper	F-ECM	Factor: 52666198803985699306925580112937986799538757577
2025-08-02	Ryan Propper	F-ECM	Factor: 838761350975792446742332334396224838945787119
2025-03-01	masser	NF-PP1	Start=116/41, B1=430000000, B2=429570000000
2025-02-01	masser	NF-PP1	Start=2/7, B1=430000000, B2=429570000000
2025-01-31	masser	NF-PP1	Start=6/5, B1=430000000, B2=429570000000
2023-10-10	-anonymous-	F-PM1	Factor: 290310479097546074437362605040796310527 / B1=100000000000, B2=122154521813133810
2023-05-17	JacobZ	NF-PM1	B1=8400000000, B2=34523926202766000
2022-02-05	Joss	NF-PM1	B1=1000000, B2=3910366209750
2021-09-13	SRJ2877	C-PRP	M13121/8883798075151/290310479097546074437362605040796310527 : 88DD75E8482DCDAE
2021-09-13	nordi	C-PRP	M13121/8883798075151/290310479097546074437362605040796310527 : 88DD75E8482DCDAE
2021-09-13	nordi	F-ECM	Factor: 290310479097546074437362605040796310527 / ECM curve 363, B1=3000000, B2=528000000, Montgomery Sigma=4821442541923566
2020-04-17	Oliver Kruse	C-PRP	M13121/8883798075151 : 88DD75E8482DCDAE
2017-10-12	kkmrkkblmbrbk	C-PRP	M13121/8883798075151 : 8CE135D75B37B59E
2017-09-21	Oliver Kruse	C-PRP	M13121/8883798075151 : 8CE135D75B37B59E
2017-09-21	Oliver Kruse	C-PRP	M13121/8883798075151 : 8CE135D75B37B59E