/usr/i686-linux-gnu/bin/readelf is in binutils-i686-linux-gnu 2.30-20ubuntu2~18.04.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/i686-linux-gnu/bin/../../bin/i686-linux-gnu-readelf
/usr/i686-linux-gnu/bin/../../bin/i686-linux-gnu-readelf