2OO
67 71 73
number of prime numbers in 71 to 80 = 3prime numbers in 71 to 80 = 71, 73, & 79
71 is a prime number.
The twentieth prime number is 71
71 is a single number and so there is no "between" possible!
It is: 71
71 is prime.
61 67 71
Halfway between them is 69.
(59 + 71) / 2 = 65
72.
76 !
1, 71.
The difference between 7 times the last digit and the rest of the number is a multiple of 71
2OO
67 or 71