It is 100, which does not belong to any other number!
The phone number belong to my friend Michael,
It is a prime number
One reason the number 89 does not belong is because it is a prime number and the other numbers are not.
4 doesn't belong because it's an even number.
It is a rational number and a real number. a positive number.
That number doesn't belong to anyone.
There is only one number, so "which number" makes no sense!
Trees
i have no answers for this sorry.
UPS
123 does not belong because it isn't in the 3s multiplication 31 does not belong because it isn't in the 3s multilplication