8 461 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

Factored

Factor	Digits	Bits	Date
1404527	7	20.4	old
491901140340111754169055330196613236710173397673	48	158.4	2025-08-09 10:52:42

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	8258 / 16550

Estimated T-Level: 47.5 ⓘ

TF below 2^153 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	BB23094BD0914461	1	0	1	3
Factored	No proof (small exponent)	2017-10-12	kkmrkkblmbrbk	BB23094BD0914461	1	1672	1	3
Factored	No proof (small exponent)	2020-04-17	Oliver Kruse	D1382EFB72429BDD	1	3954	5	3
Factored	No proof (small exponent)	2023-05-07	retsu	D1382EFB72429BDD	1	2442	5	3
Verified	No proof (small exponent)	2025-08-15	Vinickw	D1382EFB72429BDD	2	1417	5	3
Verified	No proof (small exponent)	2025-08-20	Cimaron	D1382EFB72429BDD	2	3411	5	3

History

Date	User	Type	Result
2025-08-20	Cimaron	C-PRP	M8461/1404527/491901140340111754169055330196613236710173397673 : D1382EFB72429BDD
2025-08-15	Vinickw	C-PRP	M8461/1404527/491901140340111754169055330196613236710173397673 : D1382EFB72429BDD
2025-08-09	Ryan Propper	F-ECM	Factor: 491901140340111754169055330196613236710173397673
2025-05-12	masser	NF-PP1	Start=106/41, B1=1300000000, B2=1298700000000
2023-08-23	JacobZ	NF-PM1	B1=69000000000, B2=265422648792401100
2023-05-07	retsu	C-PRP	M8461/1404527 : D1382EFB72429BDD
2021-12-16	ANONYMOUS	NF-PM1	B1=100000000
2020-04-17	Oliver Kruse	C-PRP	M8461/1404527 : D1382EFB72429BDD
2017-10-12	kkmrkkblmbrbk	C-PRP	M8461/1404527 : BB23094BD0914461
2017-09-21	Oliver Kruse	C-PRP	M8461/1404527 : BB23094BD0914461
2017-09-21	Oliver Kruse	C-PRP	M8461/1404527 : BB23094BD0914461