How to generate a string of zeroes based on a pre-determined algorithm?

I have the following code in place, and would like to condense the content of 'Update' down to a few lines at maximum. The code determines what an on-screen score counter displays, depending on the string length of the score.

 using UnityEngine;
 
 public class ScoreCounter : MonoBehaviour
 {
     public int score;
     public GameObject GameManager;
 
     void Update ()
     {
         score = GameManager.GetComponent<GameLoop>().stats.score;
         
 
         if(score.ToString().Length == 1)
         {
             this.GetComponent<TextMesh>().text = "Score: 0000" + score + "000";
         }
         else if(score.ToString().Length == 2)
         {
             this.GetComponent<TextMesh>().text = "Score: 000" + score + "000";
         }
         else if (score.ToString().Length == 3)
         {
             this.GetComponent<TextMesh>().text = "Score: 00" + score + "000";
         }
         else if (score.ToString().Length == 4)
         {
             this.GetComponent<TextMesh>().text = "Score: 0" + score + "000";
         }
         else if (score.ToString().Length == 5)
         {
             this.GetComponent<TextMesh>().text = "Score: " + score + "000";
         }
 
 
         
     }    
 }

I've calculated the number of zeroes needed in the first 'Score' string, which is:

 5 - score.ToString().Length

I'm fairly sure that the next step here is to implement it as follows:

 this.GetComponent<TextMesh>().text = "Score: " + 'insert code here with algorithm calculating zero count' + score + "000";

So the question is, what goes in that space, and if I'm completely wrong, what's the solution?

Thanks in advance for any help.