13 921 Exponent Status

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

PrimeNet Exponent Status

M_n

Details

Composite, with 1 known prime factor. Cofactor is composite.

Trial Factored to 2⁶⁸

TF target 2⁴⁴

Factored

Factor	Digits	Bits	Date
9554223263694270603601	22	73.0	old

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	640 / 640
35	1000000	1566 / 1566
40	3000000	4588 / 4588
45	11000000	1521 / 9201

Estimated T-Level: 40.8 ⓘ

TF below 2^131 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	14AD8A38D4896D32	1	0	1	3
Verified	No proof (small exponent)	2017-10-12	kkmrkkblmbrbk	14AD8A38D4896D32	1	6947	1	3
Verified	No proof (small exponent)	2020-04-17	Oliver Kruse	98C6690B68CD5C67	1	12782	5	3
Verified	No proof (small exponent)	2024-07-01	kkmrkkblmbrbk	98C6690B68CD5C67	1	6958	5	3

History

Date	User	Type	Result
2025-02-19	masser	NF-PP1	Start=185/11, B1=430000000, B2=429570000000
2025-02-09	masser	NF-PP1	Start=2/7, B1=430000000, B2=429570000000
2025-01-21	masser	NF-PP1	Start=6/5, B1=430000000, B2=429570000000
2024-07-01	kkmrkkblmbrbk	C-PRP	M13921/9554223263694270603601 : 98C6690B68CD5C67
2023-11-30	-anonymous-	NF-PM1	B1=100000000000, B2=122815096988293710
2023-05-22	JacobZ	NF-PM1	B1=7900000000, B2=32522539163164050
2023-02-11	USAFSS	NF-PM1	B1=30000000, B2=2010341563230
2022-02-06	ANONYMOUS	NF-PM1	B1=50000
2020-04-17	Oliver Kruse	C-PRP	M13921/9554223263694270603601 : 98C6690B68CD5C67
2017-10-12	kkmrkkblmbrbk	C-PRP	M13921/9554223263694270603601 : 14AD8A38D4896D32
2017-09-21	Oliver Kruse	C-PRP	M13921/9554223263694270603601 : 14AD8A38D4896D32
2017-09-21	Oliver Kruse	C-PRP	M13921/9554223263694270603601 : 14AD8A38D4896D32