FactorDB can't factorize number generated by getPrime

Question

I tried to generate big prime number and minus one then trying to find divisors but it just gave the exact number.

from factordb.factordb import FactorDB
from Crypto.Util.number import getPrime

N = getPrime(500)-1
f = FactorDB(N)
f.connect()
result=f.get_factor_list()
print(result)

etc N= 2277647640912515176017915577262253148010022211563343265354397390598683113880432667265598641213983592578231532027799084013035762860730715053597514693432 result just gave [2277647640912515176017915577262253148010022211563343265354397390598683113880432667265598641213983592578231532027799084013035762860730715053597514693432]

Answer 1

Yes, that's because the number is actually huge and FactorDB still didn't contain it.

Now that number is FF, fully factored, so you can get its factors, while when you posted this answer it was still C, "composite without known factors".

• http://factordb.com/status.html

Consider reading this documentation page about FactorDB.