To add to what Richard has said, this code can never work:
char NumberType = "POSITIVE";
NumberType = "NEGATIVE";
because NumberType is an array of characters, and so is "NEGATIVE" (string literals are stored as an array of characters because C has no concept of strings). You are trying to assign nine characters (because C strings are null terminated which means they have a "hidden character" at the end which tells the system when to stop processing it) into a single character location in a character array which will not fit.
In fact it's worse than that, because the assignment would attempt to write a pointer value (because arrays are really pointers to the data they contain) and that means it would get really messed up depending on the size of a pointer in your system.
What I'd suggest is to use a flag which says if it's position or negative (an int is fine: 0 is FALSE, non-zero is TRUE in C). So I'd do this:
#define TRUE 1
#define FALSE 0
#define POSITIVE TRUE
#define NEGATIVE FALSE
int NumberType = POSITIVE;
NumberType = NEGATVE;
printf("The number divided by 2 is %d and it's a %s number", Number, NumberType ? "POSITIVE" : "NEGATIVE");
Now your code is both more readable and easier to work with.