Cognomen 笔丹 (笔丹 
) , in the entire world, is a very rare surname. The family name 笔丹 is habitual in Eastern Asia, particularly China, where it is an extremely rare surname. More prevalently, 笔丹 is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| 笔丹 | China |