221 201 Exponent Status

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

PrimeNet Exponent Status

M_n

Status

Details

Factored

Factor	Digits	Bits	Date
1306726326617	13	40.2	old
55949420077153	14	45.7	2008-07-21 09:14:15
868985279431121	15	49.6	2009-01-07 15:56:05

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	531 / 640

Estimated T-Level: 29.1 ⓘ

TF below 2^92 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2017-09-22	Oliver Kruse	F850C9380D3CC3E2	3	0	1	3
Verified	2017-10-12	kkmrkkblmbrbk	F850C9380D3CC3E2	3	141271	1	3
Verified	2020-04-17	Oliver Kruse	8DD99ECBB9B781D7	3	1062	5	3
Verified	2024-02-03	Wentao Huang	8DD99ECBB9B781D7	3	18245	5	3

History

Date	User	Type	Result
2024-02-03	slaur	CERT	PRP Certification Proof certified good
2024-02-03	Wentao Huang	C-PRP	M221201/1306726326617/55949420077153/868985279431121 : 8DD99ECBB9B781D7 PRP proof power = 5 PRP: Verified Proof certified good
2022-03-07	Oliver Kruse	NF-PM1	B1=30000000, B2=10070832992220
2021-06-15	Oliver Kruse	NF-PM1	B1=30000000, B2=3000000000
2020-04-17	Oliver Kruse	C-PRP	M221201/1306726326617/55949420077153/868985279431121 : 8DD99ECBB9B781D7 PRP: Verified PRP without proof (small exponent)
2017-10-12	kkmrkkblmbrbk	C-PRP	M221201/1306726326617/55949420077153/868985279431121 : F850C9380D3CC3E2 PRP: Verified PRP without proof (small exponent)
2017-09-22	Oliver Kruse	C-PRP	M221201/known_factors : F850C9380D3CC3E2 PRP without proof (not generated)
2009-01-07	Matthias Wurtinger	F-ECM	Factor: 868985279431121
2008-07-21	J Feitsma	F	Factor: 55949420077153