Command line to find prime factors up to about 20-digit
echo 8467489923488383748015393693871382571541198973293077386342041917850972455728042600917611098733141289849748242918713858727104799054419363331617152109173653297177123373588445333 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 8467489923488383748015393693871382571541198973293077386342041917850972455728042600917611098733141289849748242918713858727104799054419363331617152109173653297177123373588445333 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 8467489923488383748015393693871382571541198973293077386342041917850972455728042600917611098733141289849748242918713858727104799054419363331617152109173653297177123373588445333 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 8467489923488383748015393693871382571541198973293077386342041917850972455728042600917611098733141289849748242918713858727104799054419363331617152109173653297177123373588445333 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 8467489923488383748015393693871382571541198973293077386342041917850972455728042600917611098733141289849748242918713858727104799054419363331617152109173653297177123373588445333 | ecm -n -c 2350 3e6