Surah al-Ahzab was revealed in Madinah and it has 73 ayaat.
In the commentary of Majma’ul Bayan it is narrated from the Holy Prophet (s.a.w.) that whoever recites surah al-Ahzab and also teaches it to his family members, he will be saved from the torment of the grave.
See Also: Benefits of reciting Surah Mohammad
Imam Ja’far as-Sadiq (a.s.) has said that the reward for reciting this surah often is countless and the one who does so will be under the protection of the Holy Prophet (s.a.w.) and his progeny on the Day of Reckoning.