Was the Prophet Muhammad, may Allah's prayers and peace be upon him, known as "Katham bin Abd al-Lat", and what is the authenticity of this name?

This statement is baseless. The names, titles, and biography of the Prophet, peace and blessings be upon him, are well-known and preserved. His grandfather, Abd al-Muttalib, named him "Muhammad" on the day of his birth, and this name was not common among the Arabs before then. The Qur'an and Sunnah contain some explicit names for the Prophet, peace and blessings be upon him, such as "Muhammad" and "Ahmad." The Prophet also mentioned several other names for himself, including: al-Mahi (the Eraser), al-Hashir (the Gatherer), al-Aqib (the Successor), al-Muqaffi (the Follower), Nabi al-Tawbah (the Prophet of Repentance), and Nabi al-Rahmah (the Prophet of Mercy). Some hadiths limit the names to five, while scholars have differed on the number of the Prophet's names, with some considering every description of the Prophet in the Qur'an as one of his names. In conclusion, the aforementioned statement is false and has no basis.