Command line to find prime factors up to about 25-digit
echo 290486886160546662575736888638159419711628715262487993599985616807119052358680638822667518392690983430395882050214545156707237800517912375805653307714809994015746549468855563305265784333613 | ecm -n -c 204 5e4
Command line to find prime factors up to about 30-digit
echo 290486886160546662575736888638159419711628715262487993599985616807119052358680638822667518392690983430395882050214545156707237800517912375805653307714809994015746549468855563305265784333613 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 290486886160546662575736888638159419711628715262487993599985616807119052358680638822667518392690983430395882050214545156707237800517912375805653307714809994015746549468855563305265784333613 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 290486886160546662575736888638159419711628715262487993599985616807119052358680638822667518392690983430395882050214545156707237800517912375805653307714809994015746549468855563305265784333613 | ecm -n -c 2350 3e6