NumLock can be configured to run automatically each time you login to your computer. Normally you can enable or disable this feature via the NumLock Menu bar icon. If you've hidden the menubar icon, you can also disable it from running at login via System Preferences as described by Apple.
Permanently prevent an item from opening automatically when you log in:
- Choose Apple menu > System Preferences, and then click Users & Groups.
- Select your user account, and then click Login Items.
- Select the name of the item you want to prevent from opening automatically at login.
- Click Delete (-) below the list on the right.