The Arabic word "Sultan"

[ibnjuferi]

Assalam alaikum brothers in Islam.

I am not very learned in Arabic language, and I would like to ask any of you Arabic language experts who is able to read the Quran to answer the following questions.

1. How many times the word "Sultan" appears in the Arabic Quran?
2. Please quote the verses where the word "Sultan" appears.
3. This word "Sultan" means Authority, thus, can it mean a republican authority like Syrian Arab Republic, or an absolute monarchy like Saudi Arabia?
4. If we establish a Jamaah, can the leader (Imam) of the Jamaah be called a Sultan?