6 421 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

Assignments

Assigned	User	Work Type	Stage	% Done	Updated	Est Complete	Expired
2026-02-17	VGDominion	ECM	C43S2	44.95 %	2026-02-22	2026-02-23

Factored

Factor	Digits	Bits	Date
5689007	7	22.4	old
20533981288558682247752012528450245873943	41	133.9	2021-03-25 11:35:11

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	640 / 640
35	1000000	1566 / 1566
40	3000000	4588 / 4588
45	11000000	9201 / 9201
50	44000000	2784 / 16550

Estimated T-Level: 45.8 ⓘ

TF below 2^147 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	E9C395A6F3656367	1	0	1	3
Factored	No proof (small exponent)	2017-10-12	kkmrkkblmbrbk	E9C395A6F3656367	1	4526	1	3
Factored	No proof (small exponent)	2020-04-17	Oliver Kruse	CACB07D07405EA65	1	6366	5	3
Verified	No proof (small exponent)	2021-03-26	mnd9	CACB07D07405EA65	2	6178	5	3
Verified	No proof (small exponent)	2021-03-28	Joe S.	CACB07D07405EA65	2	285	5	3

History

Date	User	Type	Result
2025-03-20	masser	NF-PP1	Start=137/29, B1=1000000000, B2=999000000000
2025-03-11	masser	NF-PP1	Start=6/5, B1=1000000000, B2=999000000000
2025-03-03	masser	NF-PP1	Start=2/7, B1=1000000000, B2=999000000000
2023-08-06	-anonymous-	NF-PM1	B1=38000000000, B2=159110268557139900
2021-08-02	ViliamF	NF-PM1	B1=500000000, B2=90500000000
2021-03-28	Joe S.	C-PRP	M6421/5689007/20533981288558682247752012528450245873943 : CACB07D07405EA65
2021-03-26	mnd9	C-PRP	M6421/5689007/20533981288558682247752012528450245873943 : CACB07D07405EA65
2021-03-25	Ryan Propper	F-ECM	Factor: 20533981288558682247752012528450245873943
2020-04-17	Oliver Kruse	C-PRP	M6421/5689007 : CACB07D07405EA65
2017-10-12	kkmrkkblmbrbk	C-PRP	M6421/5689007 : E9C395A6F3656367
2017-09-21	Oliver Kruse	C-PRP	M6421/5689007 : E9C395A6F3656367
2017-09-21	Oliver Kruse	C-PRP	M6421/5689007 : E9C395A6F3656367