apachectl: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/sbin/apachectl - from package: httpd

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/apachectl - from package: apache2

You may install the required package with command apt-get install {package}

Error in other languages:
apachectl: bevel nie gevind nie
apachectl: comandă negăsită
apachectl: comando não encontrado
apachectl: commande introuvable
apachectl: command not found
apachectl: käsku ei ole
apachectl: không tìm thấy lệnh
apachectl: komanda nerasta
apachectl: Kommando nicht gefunden.
apachectl: kommandot finns inte
apachectl: komut yok
apachectl: nie znaleziono polecenia
apachectl: níor aimsíodh an t-ordú
apachectl: no se encontró la orden
apachectl: no s'ha trobat l'ordre
apachectl: opdracht niet gevonden
apachectl: parancs nem található
apachectl: perintah tidak ditemukan
apachectl: príkaz nenájdený
apachectl: příkaz nenalezen
apachectl: команда не найдена
apachectl: командата не е открита
apachectl: 命令找不到
apachectl: コマンドが見つかりません