Command line to find prime factors up to about 45-digit
echo 4406138049467862108822304886904684665095340472558491300911579282015207482952828657413786426677152881312064869462756319604850096004769 | ecm -n -c 3961 11e6
Command line to find prime factors up to about 50-digit
echo 4406138049467862108822304886904684665095340472558491300911579282015207482952828657413786426677152881312064869462756319604850096004769 | ecm -n -c 7465 43e6
Command line to find prime factors up to about 55-digit
echo 4406138049467862108822304886904684665095340472558491300911579282015207482952828657413786426677152881312064869462756319604850096004769 | ecm -n -c 17751 11e7
Command line to find prime factors up to about 60-digit
echo 4406138049467862108822304886904684665095340472558491300911579282015207482952828657413786426677152881312064869462756319604850096004769 | ecm -n -c 42014 26e7