6 521 Exponent Status

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

PrimeNet Exponent Status

M_n

Details

Composite, with 4 known prime factors. Cofactor is composite.

Trial Factored to 2⁶⁸

TF target 2⁴⁴

Factored

Factor	Digits	Bits	Date
4890751	7	22.2	old
58438217520889	14	45.7	old
71134601241639755613468553	26	85.9	old
890373451469460569097501872209321	33	109.5	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	2539 / 16550

Estimated T-Level: 45.8 ⓘ

TF below 2^147 is very unlikely to find new factors due to ECM effort.

Status	Proof	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	No proof (small exponent)	2017-09-21	Oliver Kruse	62102214EF21F288	4	0	1	3
Verified	No proof (small exponent)	2017-10-02	kkmrkkblmbrbk	62102214EF21F288	4	0	1	3
Verified	No proof (small exponent)	2017-12-07	ATH	62102214EF21F288	4	2453	1	3
Verified	No proof (small exponent)	2020-04-17	Oliver Kruse	D2B17CA8466DA70F	4	5801	5	3
Verified	No proof (small exponent)	2024-02-03	Wentao Huang	D2B17CA8466DA70F	4	5594	5	3

History

Date	User	Type	Result
2025-03-20	masser	NF-PP1	Start=149/11, B1=1000000000, B2=999000000000
2025-03-12	masser	NF-PP1	Start=6/5, B1=1000000000, B2=999000000000
2025-03-03	masser	NF-PP1	Start=2/7, B1=1000000000, B2=999000000000
2024-02-03	Wentao Huang	C-PRP	M6521/4890751/58438217520889/71134601241639755613468553/890373451469460569097501872209321 : D2B17CA8466DA70F
2023-08-08	-anonymous-	NF-PM1	B1=38000000000, B2=159095079570076650
2021-12-17	Oliver Kruse	NF-PM1	B1=1000000000, B2=1006397938886340
2020-04-17	Oliver Kruse	C-PRP	M6521/4890751/58438217520889/71134601241639755613468553/890373451469460569097501872209321 : D2B17CA8466DA70F
2017-12-07	ATH	C-PRP	M6521/4890751/58438217520889/71134601241639755613468553/890373451469460569097501872209321 : 62102214EF21F288
2017-10-02	kkmrkkblmbrbk	C-PRP	M6521/4890751/58438217520889/71134601241639755613468553/890373451469460569097501872209321 : 62102214EF21F288
2017-09-21	Oliver Kruse	C-PRP	M6521/known_factors : 62102214EF21F288