4 721 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 2⁶⁶

TF target 2⁴⁴

TF below 2^182 is very unlikely to find new factors due to ECM effort.

P-1

B1 =	67000000000
B2 =	672059035159211700

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	16550 / 16550
55	110000000	40830 / 40830
60	260000000	29613 / 105362

Estimated T-Level: 56.4 ⓘ

Status	Date	User	Residue	Shift
Verified		Unknown	0910	0
Verified		George Woltman	1C942BA6878F8910	0
Verified		Brian J. Beesley	1C942BA6878F8910	0
Verified	2015-04-11	MadPoo	1C942BA6878F8910	2354

Assigned

Assigned	User	Work Type	Stage	% Done	Updated	Expired
2025-02-21	Jason Lynch	factor ECM small	C1S1	31.35 %	2025-02-22
2025-02-01	Kamil Gorski	factor P-1 small	S1	23.38 %	2025-02-22

History

Date	User	Type	Result
2023-08-15	masser	NF-PP1	Start=6/5, B1=1910000000, B2=341890000000
2023-07-10	masser	NF-PP1	Start=98/41, B1=1910000000, B2=76400000000
2023-05-28	-Anonymous-	NF-PM1	B1=67000000000, B2=672059035159211700
2022-06-21	Anton Repko	NF	no factor from 2^64 to 2^66
2021-05-13	ATH	NF-PP1	Start=2/7, B1=1000000000, B2=241000000000
2021-02-04	Ruslan Borisov	NF	no factor from 2^64 to 2^65
2018-08-25	snme2pm1	NF	no factor from 2^63 to 2^64
2016-12-02	snme2pm1	NF	no factor from 2^62 to 2^63
2016-11-25	-Anonymous-	NF-PM1	B1=100000000000, B2=1000000000000, E=12
2016-04-17	mikr	NF-PM1	B1=30000000000, B2=2400000000000, E=12
2016-02-23	LaurV	NF	no factor from 2^57 to 2^58
2015-06-21	Sid & Andy	NF	no factor from 2^61 to 2^62
2015-04-11	MadPoo	C-LL	1C942BA6878F8910
2015-02-12	Jayder	NF-PM1	B1=2560040779, B2=163842609831, E=12
2012-09-29	bcp19	NF	no factor from 2^60 to 2^61
2011-04-29	Joss	NF-PM1	B1=10000000000
2011-01-25	monst	NF	no factor from 2^58 to 2^60