5 528 771 Exponent Status

PrimeNet Exponent Status

M_n

Details

Composite, with 1 known prime factor. Cofactor is composite.

Trial Factored to 2⁷²

TF target 2⁶⁶

Factored

Factor	Digits	Bits	Date
261521188459737656843023	24	77.8	2025-03-30 14:09:59

ECM

Digits	B1	Curves
25	50000	76 / 280

Estimated T-Level: 21.4 ⓘ

TF below 2^66 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Shift	Software
Factored	2000-03-01	Gordon Bower	E37058B9BA231279	1122558	Windows,Prime95,v19,(aka WV1)
Factored	2000-08-10	David Beeson	E37058B9BA231279	4534673	Linux 32-bit,Prime95,v20,(aka WW2)

Status	Proof	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	Certified Good	2025-04-07	kutens	D29E4B22398DAC5E	1	4850663	5	3

History

Date	User	Type	Result
2025-04-07	joe b.	CERT	Proof certified good
2025-04-07	kutens	C-PRP	M5528771/261521188459737656843023 : D29E4B22398DAC5E Proof Certified Good Proof Power: 7
2025-03-30	fordobr	F-ECM	Factor: 261521188459737656843023 / ECM curve 33, B1=50000, B2=86479575, Edwards Sigma=4544061930871690
2021-10-31	axn	NF-PM1	B1=8000000, B2=400000000
2021-09-19	SRBase	NF	no factor TF: 71-72
2021-08-23	SRBase	NF	no factor TF: 70-71
2021-08-18	SRBase	NF	no factor TF: 69-70
2020-08-24	TJAOI	NF	no factor TF: 68-69
2019-09-09	GdS	NF-PM1	B1=200000, B2=6000000
2018-07-05	ramgeis	NF	no factor TF: 67-68
2016-07-22	Gordon Spence	NF	no factor TF: 66-67
2016-02-23	Mark Rose	NF	no factor TF: 1-62
2015-08-31	snme2pm1	NF	no factor TF: 65-66
2014-12-08	monst	NF	no factor TF: 64-65
2014-12-07	Nesowa	NF	no factor TF: 63-64
2009-05-24	Rob_Dee	NF-PM1	B1=65000, B2=1121250, E=6
2009-04-28	GrunwalderGIMP	NF	no factor TF: 62-63
2000-08-10	dmbeeson	C-LL	E37058B9BA231279
2000-07-25	dmbeeson	NF-PM1	B1=25000, B2=262500
2000-03-01	Gordon Bower	C-LL	E37058B9BA231279

Username
Password