Be forewarned. The elevators at metro stop Abbesses are being replaced. Unless you relish the idea of 90+ stairs, you might rethink your route to Montmartre.
As a follow-on to this warning, per the RATP website, the work on the elevators began on April 10, 2017 and is is scheduled to end on September 15, 2017.
Yes. And I am pretty sure it is more than 90 stairs. It, Cite and Lamarc Caulaincourt are among the deepest metro stations in Paris and use giant elevators to move people up and down. The Abbesses staircase used to have beautiful murals but the last time I walked down it, they seem to have disappeared.
Just get off at the station before Abbesses and you will be fine. It isn't much of a walk from there.
I was curious when so many people got off at Pigalle. Ha! Now I know.