You can obtain the a number for which they all divisors by calculating the least common multiple.
This way:
85 = 5*17*1
17=17*1
19=19*1
4=2^2 *1
2=2*1
The least common multiple is: 5*17*19*2^2 = 6,460.
Then 84, 17, 19, 4 and 2 are all divisors of 6,460.
