Package: atop

"atop" package binaries on CentOS:

/usr/bin/atop /usr/bin/atopd /usr/bin/atopsar

You may install this package on CentOS with yum install atop

"atop" package binaries on Debian:

/usr/bin/atop /usr/bin/atopsar

You may install this package on Debian with apt-get install atop