Your number N=140685674613168 is not product of two primes (if one of it primes is not 2) because N is even. All prime numbers ALWAYS are odd, i.e N = p*q = (2*k+1)*(2*l+1) = 4*k*l+2*(k+L)+1 = 2*(2*k*l + k+l) + 1. Member 2*(2*k*l + k+l) always even, any even number+1 = odd number. I.e product of two primes always are odd.