A number appreciate information technology (5)
I believe the answer is:
digit
'a number' is the definition.
(I know that digit is a type of integer)
'appreciate information technology' is the wordplay.
'appreciate' becomes 'dig' (to dig something is to appreciate it).
'information technology' becomes 'IT' (common abbreviation).
'dig'+'it'='DIGIT'
(Other definitions for digit that I've seen before include "A character" , "Finger; number" , "A small number" , "Single number" , "Single figure - finger" .)