פְּקֻדֵיהֶ֖ם לְמַטֵּ֣ה רְאוּבֵ֑ן שִׁשָּׁ֧ה וְאַרְבָּעִ֛ים אֶ֖לֶף וַחֲמֵ֥שׁ מֵאֽוֹת׃ (פ)
those that were numbered of them, of the tribe of Reuben, were forty and six thousand and five hundred.
Read kabbalistic (mystical) interpretation of Numbers 1:21: and classical mystical sources.