Where does “छत्तीस” come from?
छत्तीस (Hindi) comes from Sanskrit षट्त्रिंशत्, from Sanskrit त्रिंशत्, from Proto-Indo-Aryan triHśát, from Proto-Indo-Iranian triHćát, from Proto-Indo-European tridḱómt, from Proto-Indo-European tri-, from Proto-Indo-European tréyes — three.
छत्तीस (Hindi): thirty-six
Ancestry of “छत्तीस”, step by step
Words derived from “छत्तीस”