What experiment number is Leroy from the movie and Stich?

Leroy is Experiment 626, just like Stitch.

In the movie "Lilo & Stitch," Stitch is referred to as Experiment 626. Leroy is a genetic duplicate of Stitch, created by Jumba Jookiba in the sequel "Lilo & Stitch 2: Stitch Has a Glitch."