Command line to find prime factors up to about 20-digit
echo 2915614798451286268320684617618360051640181670322905894809011570550162505976580888490578221396168110357389606177278472565808362548101760201320754623521849929 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 2915614798451286268320684617618360051640181670322905894809011570550162505976580888490578221396168110357389606177278472565808362548101760201320754623521849929 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 2915614798451286268320684617618360051640181670322905894809011570550162505976580888490578221396168110357389606177278472565808362548101760201320754623521849929 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 2915614798451286268320684617618360051640181670322905894809011570550162505976580888490578221396168110357389606177278472565808362548101760201320754623521849929 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 2915614798451286268320684617618360051640181670322905894809011570550162505976580888490578221396168110357389606177278472565808362548101760201320754623521849929 | ecm -n -c 2350 3e6