At 19 June 1995 three prime factors of F13 were known:
F13 = 2710954639361 .
3603109844542291969 . c2417
The 13-digit factor was found by Hallyburton and Brillhart in 1974.
The 19-digit factors were found by Richard Crandall on Zilla net
(a network of NeXT workstations) in January and May 1991.
The quotient c2417
is a composite number with 2417 decimal digits.
On 19 June 1995 I found a fourth factor with 27 decimal digits:
p27 = 319546020820551643220672513
The quotient is c2391, a composite number with 2391 decimal digits.
F11 = 319489 . 974849 . 167988556341760475137 . 3560841906445833920513 . p564,
where p564 is a 564-digit prime number.
Since the Cruncher costs only a few thousand dollars, it is a very
For more information about the Cruncher, please contact
Harvey Dubner <Firstname@dubner.com>
22 June 1995