isprime(x)

[cino hilliard <hillcino368@hotmail.com>]

Hi,
 
My system:2003 Dell p4 2.53ghz 2gig rdram win zp pro
 
(17:14:27) gp > \v
                  GP/PARI CALCULATOR Version 2.3.4 (released)
           i686 running cygwin (ix86/GMP-4.2.1 kernel) 32-bit version
 compiled: Jul 12 2008, gcc-3.4.4 (cygming special, gdc 0.12, using dmd 0.125)
                (readline v5.2 enabled, extended help available)
 
 
I have been trying isprime(x) for x=prp with 3414 digits.
Keek getting
*** isprime: length (lg) overflow
 
What is the limit of x for isprime(x)?
 
Thanks,
Cino Hilliard