1, 3, 7 and 21. Four numbers.
1, 3, 7, 21.
1, 3, 7 and 21
Nothing can go evenly into 21 or 17. They are both odd numbers and therefore cannot be evenly divided.
They are: 3 and 7
21 has two prime factors.
21
1 ,3 ,7 ,21
1, 3, 7, 21.
21
-21
1, 3, 7, 21.
1, 3, 5, 7, 15, 21, 35, 105.
multiples of 63
1 and 7.
There are 3 prime numbers from 21 to 35:23, 29 and 31
1 and 3.
Out of those 100 numbers, 21 of them are prime numbers, so the remaining (100 - 21) = 79 are composite.