Demi Lovato: 'X Factor' Promo on 'Fallon'!

Demi Lovato goofs around with Jimmy Fallon during an appearance on Late Night With Jimmy Fallon at Rockefeller Center on Tuesday (September 3) in New York City.

The 21-year-old entertainer was joined on the show by Live with Kelly and Michael‘s Michael Strahan.

PHOTOS: Check out the latest pics of Demi Lovato

“I’m on @jimmyfallon tonight to talk about @TheXFactorUSA & Jimmy‘s high school haircut!” Demi tweeted earlier in the day.

On the same day, Demi was spotted posing for pics and signing autographs for fans while heading to the Fox And Friends Studio in the Big Apple.

FYI: Demi is wearing a Charles Albert necklace on Fallon.

25+ pictures inside of Demi Lovato making an appearance on Late Night With Jimmy Fallon…