Command line to find prime factors up to about 40-digit
echo 418907329975005632339960054567916070869171182684046608153167181595411184380621294551939992572249405380681381572083282442638168401008467033498579184154411336365436951108670975914006703302730843793253 | ecm -n -c 2036 3e6
Command line to find prime factors up to about 45-digit
echo 418907329975005632339960054567916070869171182684046608153167181595411184380621294551939992572249405380681381572083282442638168401008467033498579184154411336365436951108670975914006703302730843793253 | ecm -n -c 4413 11e6
Command line to find prime factors up to about 50-digit
echo 418907329975005632339960054567916070869171182684046608153167181595411184380621294551939992572249405380681381572083282442638168401008467033498579184154411336365436951108670975914006703302730843793253 | ecm -n -c 7542 43e6
Command line to find prime factors up to about 55-digit
echo 418907329975005632339960054567916070869171182684046608153167181595411184380621294551939992572249405380681381572083282442638168401008467033498579184154411336365436951108670975914006703302730843793253 | ecm -n -c 17767 11e7