def test_primality(n, rounds = 50):
    if mod(n,2)==0:
        return False
    for r in range(rounds):
        v = randint(1,n-1)
        if mod(jacobi_symbol(v,n),n)!=power_mod(v,floor((n-1)/2),n):
            return False
    return True

# You too can create a really big prime
n = 935839458723945
if mod(n,2)==1:
    n=n+1
while not test_primality(n):
    n = n+2
n