sister Aisha i dunno how to count the number of prophets those who were Arabs...but ALLAH has sent 300 rasool (alaihimussalam) (those who brought a new Sharee'ah) and 140,000 nabiis (alaihimussalam) (those who did not brought a new Sharee'ah)...among them, only 25 is mentioned in the Quran and another two nabiis we know from sunnah are Sheeth (alaihissalam) and Yusha' bin Noon (alaihissalam)...so total 27 we know...alhamdhulillah..
We don't know for sure how many prophets (PBUT) were sent to the arab (the tribes who used to live in the arabic peninsula) because only three were mentioned explicitly in some hadiths. Then the known arabic prophets (PBUT) are:
1. Hud (PBUH)
2. Saleh (PBUH)
3. Muhammad (PBUH)