Whats the smallest number ("the magic number") that can satisfy these conditions?

- its positive

- it is not divisible by any number below 20 (excluding 1)

- the average of the digits is an even number between 3 and 9

To Victor Zapana

The special number is 53

the numbers not divisible by any number <20 should be prime and greater than 20

The numbers are 23,29,31,37,41,43,47,53,59,61 and so on.

The least number with avg of digits as a +ve integer between 3 and 9 (4,6,8) is 53

sum=8, avg=4