It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) passed away when he (peace and blessings be upon him) was sixty-five (65) years old, and Sayyiduna Abu Bakr (may Allah be pleased with him) also passed away at the same age, Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) passed away at the age of fifty-six (56), and Sayyiduna Uthman (may Allah be pleased with him) passed away at the age of eighty-one (81).
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10764