Ubuntu Server Change Open Files Limits

$[texteditor]$

ulimit -a

sudo $texteditor$ /etc/security/limits.conf

*       soft    nofile  500000
*       hard    nofile  500000
root    soft    nofile  500000
root    hard    nofile  500000
*       soft    core    unlimited
*       hard    core    unlimited
root    soft    core    unlimited
root    hard    core    unlimited

How many files opened by $program$

$[program]$

lsof -n -c $program$ | wc