Yes, NUMBERER is a Scrabble word!

Letter values in Scrabble US: N 1, U 1, M 3, B 3, E 1, R 1, E 1, R 1.

Is it a valid word?

NUMBERER is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

lacking sensation
(followed by `to') not showing human feeling or sensitivity; unresponsive
so frightened as to be unable to move; stunned or paralyzed with terror; petrified