I have this `DF1`:

```
           cpf 
702.464.462-18    
067.282.769-71    
017.811.255-03    
806.392.831-87    
074.256.613-73    
080.405.147-03    

```

And this other one `DF2`:

```
          cpf   
1:  6685540966   
2:  1301301922   
3: 80673503020   
4: 13575505705  
5: 36752823847  
6:  1756061459

```

I'd like to format these numbers, so the `DF2` can be the same as the `DF1`, like this:

```
          cpf   
1:  066.855.409-66   
2:  013.013.019-22   
3:  806.735.030-20   
4:  135.755.057-05  
5:  367.528.238-47  
6:  017.560.614-59

```

So basically i need to transform them into a 11 digit number with 0's, and specify the punctuiation like that.
Any ideas how to do it?

EDIT:
Using the `str_pad` from the`stringr` packaged i did:

```
str_pad(DF2$cpf, 11, pad = "0")

```

And it worked. However i don't know how to set the punctuation.