Command line to find prime factors up to about 25-digit
echo 181593351895636688169886699817387676117985256563303224919353884873246189498818407803832094655575356349876808322717344286430356096214291 | ecm -n -c 204 5e4
Command line to find prime factors up to about 30-digit
echo 181593351895636688169886699817387676117985256563303224919353884873246189498818407803832094655575356349876808322717344286430356096214291 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 181593351895636688169886699817387676117985256563303224919353884873246189498818407803832094655575356349876808322717344286430356096214291 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 181593351895636688169886699817387676117985256563303224919353884873246189498818407803832094655575356349876808322717344286430356096214291 | ecm -n -c 2350 3e6