The word philosophy was probably coined by Pythagoras.  
his theorem is very good
Pythagoras's theorum has more to do with math than philosophy.  
true, but everything is related
Pythagoreanism
Pythagoreanism originated in the 6th century BC, based on the teachings and beliefs held by Pythagoras and his followers, the Pythagoreans. Pythagoras established the first Pythagorean community in Crotone, Italy. Early Pythagorean communities spread throughout Magna Graecia.
Pythagoras’ death and disputes about his teachings led to the development of two philosophical traditions within Pythagoreanism. The "akousmatikoi" were superseded in the 4th century BC as a significant mendicant school of philosophy by the Cynics. The "mathēmatikoi" philosophers were absorbed into the Platonic school in the
tetractys was "so admirable, and so divinised by those who understood [it]," that Pythagoras's students would swear oaths by it. Andrew Gregory concludes that the tradition linking Pythagoras to the tetractys is probably genuine.
Modern scholars debate whether these numerological teachings were developed by Pythagoras himself or by the later Pythagorean philosopher Philolaus of Croton. In his landmark study "Lore and Science in Ancient Pythagoreanism", Walter Burkert argues that Pythagoras was a charismatic political and religious teacher, but that the number philosophy attributed to him