The number is 1.
one
Just 1.
64 and 81 ; 64 is 8 squared and 81 is 9 squared
The square root of any number between 64 and 81.The square root of any number between 64 and 81.The square root of any number between 64 and 81.The square root of any number between 64 and 81.
81
81
81
64 and 81 are squares of whole numbers. 64 is the square of 8 (8x8=64) and 81 is the square of 9 (9x9=81).
The greatest common factor of both numbers is 3
27 and 81
Work backwards. 64+17 is 81. 81/3 is 27