Command line to find prime factors up to about 20-digit
echo 34534789953495659004561276491788578261120090181646171792607668259906442243777383599734730935225864067327039970154269654631918504722544215669407714815691866372589863 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 34534789953495659004561276491788578261120090181646171792607668259906442243777383599734730935225864067327039970154269654631918504722544215669407714815691866372589863 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 34534789953495659004561276491788578261120090181646171792607668259906442243777383599734730935225864067327039970154269654631918504722544215669407714815691866372589863 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 34534789953495659004561276491788578261120090181646171792607668259906442243777383599734730935225864067327039970154269654631918504722544215669407714815691866372589863 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 34534789953495659004561276491788578261120090181646171792607668259906442243777383599734730935225864067327039970154269654631918504722544215669407714815691866372589863 | ecm -n -c 2350 3e6