1 898 419 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
27208590476354901511832506610471	32	104.4	2015-10-08 10:46:09

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	106 / 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
Verified (Factored)		Geoffrey Luders	F65422EB967F61A9	0
Verified (Factored)	1999-01-02	Cody DW Jones	F65422EB967F61A9	883386
Verified (Factored)	2015-06-27	MadPoo	F65422EB967F61A9	913871

Status	Date	User	Residue	Shift	Type	Base
Verified (Factored)	2025-09-02	Kriesel	42F40A616C05B823	0	1	3

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2017-09-30	alpertron	05D2594F133783CA	1	0	1	3
Verified	2017-10-20	Oliver Kruse	05D2594F133783CA	1	1476345	1	3

P-1 factors

Date	Factor	B1	B2
2015-10-08	27208590476354901511832506610471	500000	15000000

History

Date	User	Type	Result
2025-09-03	benthomas	CERT	PRP Certification CERT proof power = 6 Proof certified good
2025-09-02	Kriesel	C-PRP	42F40A616C05B823 PRP proof power = 6 PRP: Verified (Factored) Proof certified good
2022-03-08	LordJulius	NF	no factor from 2^58 to 2^60
2017-10-20	Oliver Kruse	C-PRP	M1898419/27208590476354901511832506610471 : 05D2594F133783CA PRP: Verified PRP without proof (not generated)
2017-09-30	alpertron	C-PRP	M1898419/27208590476354901511832506610471 : 05D2594F133783CA PRP: Verified PRP without proof (not generated)
2015-10-08	Bruno Victal	F-PM1	Factor: 27208590476354901511832506610471 / (P-1, B1=500000, B2=15000000, E=12)
2015-09-13	ramgeis	NF	no factor from 2^65 to 2^66
2015-06-27	MadPoo	C-LL	F65422EB967F61A9
2015-05-12	snme2pm1	NF	no factor from 2^64 to 2^65
2015-05-12	snme2pm1	NF	no factor from 2^63 to 2^64
2012-01-23	markr	NF-PM1	B1=275000, B2=6000000, E=12
2011-03-08	GrunwalderGIMP	NF	no factor from 2^1 to 2^63
2010-04-11	Architects Cubed	NF	no factor from 2^60 to 2^61