Yes, the cultural symbolism of that number came to mind first (although some people might consider it a racist stereotype): I picture Numberblock 1001 as a genie-like character with a rainbow-colored turban and an Arab accent. His default shape is a tall, narrow three-dimensional "box" (7 blocks wide. 13 tall, 11 deep) built from red cubes, in the same shade as One or One Thousand. A pair of hazy white arms extends from the character's sides; a whirlwind-like trail extends below him, enabling 1001 to fly. By reciting his three "magic factors" (7, 11, 13) this Numberblock can grant his friends' wishes. Being related to both Seven and Thirteen, though, gives 1001 a paradoxical twist: if there's a way for the wish to backfire or have odd side effects, it will.