The number shows BJ, I guess they may use phone card. The phone card companies would hook up with a local number to deliver the phone. Everytime could be different.
Also normally Admissions won't call the candidates unless they have a great interest in him or her. Either ready to admit and doublecheck, or hesitatent, (make the call to help them make the final decision). Either case, you got to Ace on this phone. But cool, make sure u know what they are asking and confident and positive. If possible, try some Chit Chat. Crack some jokes. also remember some great things you learn about the School you applied and make a good case of why you want to choose it.