/usr/libx32/libatomic.so.1 is in libx32atomic1 5.4.0-6ubuntu1~16.04.10.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/libx32/libatomic.so.1.1.0
/usr/libx32/libatomic.so.1.1.0