/usr/lib/x86_64-linux-gnu/libatkmm-1.6.so is in libatkmm-1.6-dev 2.22.7-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libatkmm-1.6.so.1.1.0
/usr/lib/x86_64-linux-gnu/libatkmm-1.6.so.1.1.0