[qebuzjyl] Factoring 512 bits with Pari/GP

The largest prime number less than 2^(2^9) is p=2^512-569. The factorization of p-1, that is, 2^512-570 is

? factorint(precprime(2^512)-1)
time = 6h, 8mn, 41,900 ms.
%17 =
[2 1]
[23 1]
[41 1]
[353 1]
[105095387 1]
[45130584520747958722981 1]
[582271299047893027187874292913927407 1]
[2440563294432588452310063876982204011061 1]
[2987936166061269764733822017919288608395313 1]

The least primitive root is 7.

Previous calculation for 1024 and attempt at 2048.