15 250 121 Exponent Status

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

PrimeNet Exponent Status

M_n

Status

Details

Composite: proven not-prime with Lucas-Lehmer test

TF

No factors below 2⁷⁴

TF target 2⁶⁹

P-1

B1 =	1700000
B2 =	623218050

ECM

Digits	B1	Curves
25	50000	1 / 280

Estimated T-Level: 20.0 ⓘ

Status	Date	User	Residue	Shift
Verified	2002-06-15	Kim Neve	45B69D9B575F0B78	14901032
Verified	2006-10-24	Andrew China	45B69D9B575F0B78	2166286

History

Date	User	Type	Result
2024-09-11	Sid & Andy	NF-PM1	B1=1700000, B2=623218050
2022-02-27	TheJudger	NF	no factor from 2^73 to 2^74
2022-02-27	TheJudger	NF	no factor from 2^72 to 2^73
2021-10-15	-Anonymous-	NF	no factor from 2^71 to 2^72
2021-09-06	SRBase	NF	no factor from 2^70 to 2^71
2021-06-22	lycorn	NF	no factor from 2^69 to 2^70
2017-12-27	ramgeis	NF	no factor from 2^68 to 2^69
2017-12-27	ramgeis	NF	no factor from 2^67 to 2^68
2016-10-16	Tha	NF-PM1	B1=300000, B2=6000000, E=12
2016-03-16	Mark Rose	NF	no factor from 2^65 to 2^66
2014-05-28	Nesowa	NF	no factor from 2^66 to 2^67