5 261 Exponent Status

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

PrimeNet Exponent Status

M_n

Status

Details

Composite, with 2 known prime factors. Cofactor is composite.

Factored

Factor	Digits	Bits	Date
42089	5	15.4	old
1726756873978991	16	50.6	old

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	8429 / 16550

Estimated T-Level: 47.5 ⓘ

TF below 2^153 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2017-09-21	Oliver Kruse	05F198CA35E0FE57	2	0	1	3
Verified	2017-10-12	kkmrkkblmbrbk	05F198CA35E0FE57	2	2387	1	3
Verified	2020-04-17	Oliver Kruse	2343B7F3E8FA10D6	2	1396	5	3
Verified	2024-02-03	Wentao Huang	2343B7F3E8FA10D6	2	3561	5	3

History

Date	User	Type	Result
2024-02-03	Wentao Huang	C-PRP	M5261/42089/1726756873978991 : 2343B7F3E8FA10D6 PRP: Verified PRP without proof (small exponent)
2023-12-01	mikr	NF-PM1	B1=500000000000, B2=1311295166917335600
2023-06-28	-Anonymous-	NF-PM1	B1=60000000000, B2=253175458787951700
2022-01-24	Ethan O'Connor	NF-PM1	B1=1300000000
2021-12-16	Oliver Kruse	NF-PM1	B1=1000000000, B2=1002849399191640
2021-12-15	Lisander Viaene	NF-PM1	B1=101101101, B2=242033299467960
2020-04-17	Oliver Kruse	C-PRP	M5261/42089/1726756873978991 : 2343B7F3E8FA10D6 PRP: Verified PRP without proof (small exponent)
2017-10-12	kkmrkkblmbrbk	C-PRP	M5261/42089/1726756873978991 : 05F198CA35E0FE57 PRP: Verified PRP without proof (not generated)
2017-09-21	Oliver Kruse	C-PRP	M5261/42089/1726756873978991 : 05F198CA35E0FE57 PRP: Verified PRP without proof (not generated)
2017-09-21	Oliver Kruse	C-PRP	M5261/42089/1726756873978991 : 05F198CA35E0FE57 PRP without proof (not generated)