Numbers 2:6 Midrash

וּצְבָא֖וֹ וּפְקֻדָ֑יו אַרְבָּעָ֧ה וַחֲמִשִּׁ֛ים אֶ֖לֶף וְאַרְבַּ֥ע מֵאֽוֹת׃ (ס)

and his host, even those that were numbered thereof, fifty and four thousand and four hundred;