In all Germanic languages (such as English and German), 13 is the first compound number (in German dreizehn); the numbers 11 and 12 have their own names (in German elf and zwölf).
In Germany, according to an old tradition, 13 (dreizehn) as the first compound number was the first number written in digits; the numbers 0 (null) through 12 (zwölf) were spelt out.