Anything divided by 1 is always itself.
2 squared 1 = 4 so the divisibility rule is that it is divisible by 1, 2 and 4.
By tautology. If it did not work, it would not be a divisibility rule!
What is the divisblity rule by 8
The special divisibility rule of 17 is "Take the difference of the rest of the digits and the last digit times 5." For instance: 17 1 - 7 * 5 = 1 - 35 = -34 which is divisible by 17.
There is no easy rule for divisibility by 34.
The divisibility rule for 2 works because the base of our number system, 10, is divisible by 2.
Able to Be Divided
2.50
13 is a prime number - it can only be divided by 1 and itself (for an integer answer).
1, 2, 3 and 4
1, 2, 4 and 47
Judging by some of the questions asked on this site, the first rule is that divisibility is a concept that applies only to whole numbers.