8 proper factors: 2,4,5,8,10,16,20,40.
A Proper factor is any positive integer that divides your number, and we exclude 1 and the number itself.
None.
1,3,27 and 81
By any of its factors including itself
Nine proper factors: 1 2 4 5 10 20 25 50 100.
3 and 29
91 has 4 factors (2 of them which are proper). Those factors are:{1, 7, 13, 91}
No. Some proper factors are prime.
No, no prime number has proper factors.
1 doesn't have proper factors.
One has no proper factors.
The greatest factor of 89 is 89.
The proper factors of 26 are 2 and 13