Nah, it's Ancient Greek (Athenian to be precise). They wrote their numbers in one big string like this:
πεντακισχιλιοιεπτακοσιοιεβδομηκονταεπτά
Though really, it's just a collection of multiple number words:
πεντακισχίλιοι (5000) + ἑπτακόσιοι (700) + ἑβδομήκοντα (60) + ἑπτά (7)