SQL unexpected result when mixing numbers and strings

Question

I have no idea why this happens. Sql statement below returns 'test2'. Why does it do that? It seems like it only captures the first number of the string I gave. I expected an empty result.

Query:

SELECT article FROM news WHERE id = '2aas13'

Table 'news':

id | article
------------
1  | test
2  | test2
3  | test3

Database used: mysql