The Arabic word for successor / caliph / vicegerent is خَلِيفَة (khaleefah).. This word appears 9 times in the Quran.
149x👑
خَلِيفَة
khaleefah
successor / caliph / vicegerent
جَعَلَ اللهُ آدَمَ خَلِيفَةً فِي الأَرْضِ.
Adam was made a vicegerent on earth.