Greek numeral

Greek numerals are a system of writing numbers using the letters of the Greek alphabet. These alphabetic numerals are also known as Ionic or Ionian numerals, Milesian numerals, or Alexandrian numerals. In modern Greece, they are still used for ordinal numbers and in contexts similar to those in which Roman numerals are still used elsewhere in the West. For ordinary cardinal numbers, however, Greece uses Arabic numerals.

The Minoan and Mycenaean civilizations' Linear A and Linear B alphabets used a different system, called Aegean numerals, which included specialized symbols for numbers: ...
Wikipedia