The Messenger of Allah (صلى الله عليه و سلم) said:
إِنَّ لِلَّهِ تِسْعَةً وَتِسْعِينَ اسْمًا مِائَةً إِلاّ وَاحِدًا مَنْ أَحْصَاهَا دَخَلَ الْجَنَّةَ .
Translation: Indeed, Allah has 99 names (one hundred minus one); whoever memorizes them will enter Jannah. [Saheed Bukhari and Saheeh Muslim]