Command line to find prime factors up to about 20-digit
echo 1707261785010448898542931655293904776314770671755562750693160171208243512967130694350462705756368676588481618831929183853545308859467554174143920854544575560837699 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 1707261785010448898542931655293904776314770671755562750693160171208243512967130694350462705756368676588481618831929183853545308859467554174143920854544575560837699 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 1707261785010448898542931655293904776314770671755562750693160171208243512967130694350462705756368676588481618831929183853545308859467554174143920854544575560837699 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 1707261785010448898542931655293904776314770671755562750693160171208243512967130694350462705756368676588481618831929183853545308859467554174143920854544575560837699 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 1707261785010448898542931655293904776314770671755562750693160171208243512967130694350462705756368676588481618831929183853545308859467554174143920854544575560837699 | ecm -n -c 2350 3e6