There are 36 black keys on a standard 88-key piano. The black keys represent sharps and flats. A standard piano with 88 keys has 52 white keys. The white keys are the natural notes.
An 88-key piano has seven octaves plus three lower notes (B, B flat and A) below the bottom C. It has 52 white keys and 36 black keys (sharps and flats), with each octave made up of seven white keys ...