Command line to find prime factors up to about 35-digit
echo 1303937083905476997501540852798070957677781158059309006089273235934202003529500093511127391163266404301634990770786547912566140543169063266270658616274046756970645414747280602308503190694407555601452288281206053 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 1303937083905476997501540852798070957677781158059309006089273235934202003529500093511127391163266404301634990770786547912566140543169063266270658616274046756970645414747280602308503190694407555601452288281206053 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 1303937083905476997501540852798070957677781158059309006089273235934202003529500093511127391163266404301634990770786547912566140543169063266270658616274046756970645414747280602308503190694407555601452288281206053 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 1303937083905476997501540852798070957677781158059309006089273235934202003529500093511127391163266404301634990770786547912566140543169063266270658616274046756970645414747280602308503190694407555601452288281206053 | ecm -n -c 7553 43e6