21,22,23,24,25,26,27,28,29
The prime numbers between 20 and 30 are 23 and 29.
All of them except 23 and 29 which are prime numbers having only two factors
Including 20 and 30 there are ten of them
17, 19, 23, 29
LCM for 20 and 30 is 60.
They are two composite numbers and they add up to 56 which is also a composite number
A common denominator of 20 and 30 is 600. This is NOT the least common denominator, though.
Gioachino Rossini
"between" requires two numbers, for example, between 20 and 30 or between 20 and 1000. You have not specified the other number.
There are no whole numbers between 20 and 21. Only fractions or decimals exist between these two numbers. Whole numbers between 20 and 25 are 21, 22, 23, and 24.
The square numbers between 1 and 20 are 1,4,9 and 16.
There are 69 odd numbers between 20 and 158.