1 397 999 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
2795999	7	21.4	old
1563420468892514612111	22	70.4	2017-11-15 10:10:04

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	105 / 640

Estimated T-Level: 25.8 ⓘ

TF below 2^81 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Shift	Type	Base
Verified (Factored)	2025-09-01	Kriesel	BBFA5AD986A46537	0	1	3

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified (Factored)	2017-09-30	Oliver Kruse	FBA729A1147577F5	1	0	1	3
Verified (Factored)	2017-10-25	kkmrkkblmbrbk	FBA729A1147577F5	1	258271	1	3
Verified	2017-11-16	kkmrkkblmbrbk	BBFA5AD986A46537	2	1039059	5	3
Verified	2017-11-16	Oliver Kruse	BBFA5AD986A46537	2	1345874	5	3

History

Date	User	Type	Result
2025-09-03	Carlos Pinho	CERT	PRP Certification CERT proof power = 6 Proof certified good
2025-09-01	Kriesel	C-PRP	BBFA5AD986A46537 PRP proof power = 6 PRP: Verified (Factored) Proof certified good
2017-11-16	Oliver Kruse	C-PRP	M1397999/2795999/1563420468892514612111 : BBFA5AD986A46537 PRP: Verified PRP without proof (not generated)
2017-11-16	kkmrkkblmbrbk	C-PRP	M1397999/2795999/1563420468892514612111 : BBFA5AD986A46537 PRP: Verified PRP without proof (not generated)
2017-11-15	storm5510	F-ECM	Factor: 1563420468892514612111 / (ECM curve 3, B1=50000, B2=5000000)
2017-10-25	kkmrkkblmbrbk	C-PRP	M1397999/2795999 : FBA729A1147577F5 PRP: Verified PRP without proof (not generated)
2017-09-30	Oliver Kruse	C-PRP	M1397999/2795999 : FBA729A1147577F5 PRP: Verified PRP without proof (not generated)
2016-03-17	alpertron	NF-PM1	B1=500000, B2=15000000, E=12