The word "between" implies two values. There cannot be anything between a single item.
71 is a single number and so there is no "between" possible!
It is: 71
71 is prime.
61 67 71
(59 + 71) / 2 = 65
Halfway between them is 69.
72.
76 !
2OO
67 or 71
67 71 73
The answer could be any number between 39 to 45. When doubled this produces 78 to 90. and with 7 subtracted this gives 71 to 83.