Pythais
Yes. His name is on it.
They were known as the Pythagoreans.
Pythagoras
Pythagoras wife is Theano.
He had two or three brothers and no sisters
Pythagoras's older brothers were Eunomus and Tyrrhenus. His father was Mnesarchus. His mother was known as Parthenis in her early life, but later took the name Pythais. His wife was Theano. His daughters were Myia or Myria, Damo and Arignote. His sons were Arimnestes and Telauges.
He was simply known as Pythagoras of Samos.
Pythagoras of Samos
His only name in historical record is Pythagoras, he is sometimes called Pythagoras of Samos
Pythagoras.
Pythagoras
The name for the followers of Pythagoras was the Pythagoreans.
Pythagoras's mother's name was Pythais.
His full name was simply "Pythagoras."
He had two or three brothers and no sisters
There is no reliable historical record that allows historians to determine whether or not Pythagoras had any siblings.