The Prophet (ﷺ) used to recite more than seventy times a day:

أَسْتَغْفِرُ اللَّهَ وَأَتُوْبُ إِلَيْهِ

Astaghfirullaaha wa 'atoobu 'ilayhi

I seek the forgiveness of Allah and repent to Him.

Reference: Bukhari: 6307