ćs3LR×0KJ‚€{íË
Try it online or verify all test cases.
Explanation:
ć # Extract the head of the (implicit) input-list;
# pop the list and push the remainder-list and head separately to the stack
s # Swap to get the remainder-list at the top again
3LR # Push the list [3,2,1]
× # Repeat the remainder-numbers that many times as string
0K # Remove all 0s (so all "0", "00" and "000")
J # Join the strings in the list together
‚ # Pair this string with the head
€{í # Sort the digits in both strings in descending order
Ë # And check if both are now equal
# (after which the result is output implicitly as result)