6 661 Exponent Status

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

PrimeNet Exponent Status

M_n

Status

Details

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

Factored

Factor	Digits	Bits	Date
33930121529	11	35.0	old
136375449383697285680873	24	76.9	old
221318810814268688188345577	27	87.5	old
2151658218506455706693588763548437578564131115761	49	160.6	2021-03-27 16:50:14

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	4513 / 16550

Estimated T-Level: 46.4 ⓘ

TF below 2^149 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified (Factored)	2017-09-21	Oliver Kruse	B9B9B9A7F1645679	3	0	1	3
Verified (Factored)	2017-10-02	kkmrkkblmbrbk	B9B9B9A7F1645679	3	0	1	3
Verified (Factored)	2017-12-07	ATH	B9B9B9A7F1645679	3	5593	1	3
Verified (Factored)	2020-04-17	Oliver Kruse	5668BD640061EB03	3	6268	5	3
Verified	2021-03-27	mikr	5668BD640061EB03	4	1643	5	3
Verified	2021-03-28	mikr	5668BD640061EB03	4	3240	5	3
Verified	2021-03-30	rbanov	5668BD640061EB03	4	4549	5	3
Verified	2023-04-08	Dobri	5668BD640061EB03	4	5866	5	3

History

Date	User	Type	Result
2023-08-11	-Anonymous-	NF-PM1	B1=37000000000, B2=148599418701633900
2023-04-15	Naegi Makoto	NF-PM1	B1=10000000000, B2=50135831001656400
2023-04-08	Dobri	C-PRP	M6661/33930121529/136375449383697285680873/221318810814268688188345577/2151658218506455706693588763548437578564131115761 : 5668BD640061EB03 PRP: Verified PRP without proof (small exponent)
2021-12-17	Oliver Kruse	NF-PM1	B1=1000000000, B2=1003954060639530
2021-03-30	rbanov	C-PRP	M6661/33930121529/136375449383697285680873/221318810814268688188345577/2151658218506455706693588763548437578564131115761 : 5668BD640061EB03 PRP: Verified PRP without proof (small exponent)
2021-03-28	mikr	C-PRP	M6661/33930121529/136375449383697285680873/221318810814268688188345577/2151658218506455706693588763548437578564131115761 : 5668BD640061EB03 PRP: Verified PRP without proof (small exponent)
2021-03-27	mikr	C-PRP	M6661/33930121529/136375449383697285680873/221318810814268688188345577/2151658218506455706693588763548437578564131115761 : 5668BD640061EB03 PRP: Verified PRP without proof (small exponent)
2021-03-27	Ryan Propper	F-ECM	Factor: 2151658218506455706693588763548437578564131115761 / (ECM curve 1, B1=43000000, B2=198654756318, Sigma=8281034078962364000)
2020-04-17	Oliver Kruse	C-PRP	M6661/33930121529/136375449383697285680873/221318810814268688188345577 : 5668BD640061EB03 PRP: Verified PRP without proof (small exponent)
2017-12-07	ATH	C-PRP	M6661/33930121529/136375449383697285680873/221318810814268688188345577 : B9B9B9A7F1645679 PRP: Verified PRP without proof (small exponent)
2017-10-02	kkmrkkblmbrbk	C-PRP	M6661/33930121529/136375449383697285680873/221318810814268688188345577 : B9B9B9A7F1645679 PRP: Verified PRP without proof (not generated)
2017-09-21	Oliver Kruse	C-PRP	M6661/known_factors : B9B9B9A7F1645679 PRP without proof (not generated)