Have you looked into the work from these following investigators?

Drs. Taubert and Parr (Emory University, Yerkes National Primate Research Center) have published several studies on recognition memory for faces in chimpanzees (2017, Anim Cogn, 20(2): 321-329).

Drs. Rosati & Hare (Duke University) have published on spatial memory in chimpanzees and bonobos (2012, Dev Sci, 15(6): 840-853).

Dr. Hopkins (Georgia State University, Yerkes National Primate Research Center) has published several studies about cognitive abilities in chimpanzees and bonobos, including referential communication (2014, Anim Cogn, 17(1):85-94).

Hi Majid, i hope the following information will be useful:

Article Numerical memory span in a chimpanzee

Article Symbolic representation of number in chimpanzees

Dear Majid Manoochehri , this paper on chimpanzee's working memory can also be useful:

Article Working memory of numerals in chimpanzees