Any of its factors which are: 1, 3, 9, 27 and 81
Just 1.
1. The numbers are co-prime
These numbers: 1, 3, 9, 27, 81, 243.
The greatest common factor of both numbers is 3
It is: 81 which is the HCF
1 and 81 Those two numbers certainly divide into 81 though they are not the only numbers to do so.
9 x 9 = 81 These numbers go into 81: 1, 3, 9, 27, 81.
81*81 is rational. Rational numbers are numbers that can be written as a fraction. Irrational numbers cannot be expressed as a fraction.
81 is a composite number.
The greatest common factor for the numbers 27 and 81 are 27.
The greatest common factor of the numbers 36 and 81 is 9.
Techcially all numbers are divisible by 81, however many would result in a decimal answer. If you mean how many numbers are divisible by 81 and have an integer answer, then it is "all multiples of 81" - e.g 81 x 2, 81 x 3 etc...81, 162, 243 and keep adding 81 forever.