It is a Prime number
31 because 3+4=7+4=11+4=15+4 does not equal 31
It is 100, which does not belong to any other number!
The phone number belong to my friend Michael,
31 is a prime number
31 is a whole number and it is also a prime number
123 does not belong because it isn't in the 3s multiplication 31 does not belong because it isn't in the 3s multilplication
31 (the rest are all multiples of 3).
3
31 because 3+4=7+4=11+4=15+4 does not equal 31
1 and 31 (31 is a Prime number).
It is 100, which does not belong to any other number!
1 and 31. 31 is a prime number.
An infinite number of multiples of 31 can be divided by 31.
The phone number belong to my friend Michael,
31 is a prime number
31 is a whole number and it is also a prime number
The only 'factors' of '31' are '1' & '31', because '31' is a prime number.