It is translatable, indirectly. The fields maintained in the Launchpad Designer or the Launchpad App Manager are only default values. The fields of dynamic tiles can be overwritten by the service, which returns the number (see link below). That means, that you could return the field numberUnit depending on the login language of the user (e.g. as text-field).

See SAP Help (latest)
https://help.sap.com/docs/ABAP_PLATFORM_NEW/a7b390faab1140c087b8926571e942b7/be50c9a40b504083a7c75baaa02a85fa.html?locale=en-US&version=LATEST