8 861 Exponent Status

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

PrimeNet Exponent Status

M_n

Status

Details

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

Factored

Factor	Digits	Bits	Date
31389429768089	14	44.8	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	10831 / 16550

Estimated T-Level: 48.3 ⓘ

TF below 2^155 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	E8E9782B41BC331D	1	0	1	3
Verified	2017-10-12	kkmrkkblmbrbk	E8E9782B41BC331D	1	5234	1	3
Verified	2020-04-17	Oliver Kruse	ECD7F85DC4B8C30C	1	5967	5	3
Verified	2024-07-01	kkmrkkblmbrbk	ECD7F85DC4B8C30C	1	4243	5	3

History

Date	User	Type	Result
2024-07-01	kkmrkkblmbrbk	C-PRP	M8861/31389429768089 : ECD7F85DC4B8C30C PRP: Verified PRP without proof (small exponent)
2023-08-04	JacobZ	NF-PM1	B1=66000000000, B2=254680416808818000
2021-12-16	Lisander Viaene	NF-PM1	B1=100000000
2020-04-17	Oliver Kruse	C-PRP	M8861/31389429768089 : ECD7F85DC4B8C30C PRP: Verified PRP without proof (small exponent)
2017-10-12	kkmrkkblmbrbk	C-PRP	M8861/31389429768089 : E8E9782B41BC331D PRP: Verified PRP without proof (not generated)
2017-09-21	Oliver Kruse	C-PRP	M8861/31389429768089 : E8E9782B41BC331D PRP: Verified PRP without proof (not generated)
2017-09-21	Oliver Kruse	C-PRP	M8861/31389429768089 : E8E9782B41BC331D PRP without proof (not generated)