The statement that is NOT a fact about the heap is:
"A heap is ordered, sequential, and smaller than a stack."
This statement is incorrect because a heap does not have to be ordered or sequential (in fact, the term "heap" refers to a type of data structure where certain properties are maintained, such as the heap property for heaps used in algorithms, but this does not imply sequential ordering). Additionally, the size of a heap is not inherently smaller than a stack; it depends on the specific usage and allocation of memory in the application.