Yes, PRAYERS is a Scrabble word!

Letter values in Scrabble US: P 3, R 1, A 1, Y 4, E 1, R 1, S 1.

Is it a valid word?

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

the act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)
reverent petition to a deity
earnest or urgent request
a fixed text used in praying
someone who prays to God