Yes!!! It is '5'.
Remember
4 x 5 = 20
2 x 2 x 5 = 20
20
Yes, 3 and 20 are relatively prime because they have no common factor greater than 1.
11, 13, 17, 19
4 is greater than 3 and is a factor of 20.
23 is the smallest prime number greater than 20.
The prime number that is greater than 20 but less than 29 is 23.
23 and 29 are the two prime numbers greater than 20 but less than 30.
23
fifteen
23 and 29 are the prime numbers between 20 and 30.
The numbers 23 and 29 are prime.
23 and 29
485 = 5 x 97 which are both prime numbers so your question has no answer other than 485 itself.