While there are many implications in the Hebrew alphabet, the number 13 - traditionally bad luck in modern cultures, does not share the same stigma in the Jewish traditions. Numerology has not made it a taboo number either.
In the Jewish culture, 13 is the age when a boy becomes a man at his bar mitzvah. There are Thirteen Principles that sum up the Jewish beliefs, and there are 13 Attributes of Mercy in Ex. 34: 6-7.
The number, generally written Yod-Gimel, has a numerical value that equates with love and a daily prayer declaration that "G-d is one".
This rich tradition of numeric value and religious or social importance gives the Jewish culture a proud heritage with the Hebrew language preserving so many facets in a few characters.
Hebrew Has a Fascinating History
The Different Types of Hebrew
The Dialects of Hebrew Language
Eliezer Ben-Yehuda: Pioneer of the Hebrew Language
Learning the Hebrew Language
The Origins of Hebrew
Modern Hebrew: Strengthening the Language
Yiddish is a Dying Language
Using Hebrew as an Everyday Language
The 4000 Year Old Phoenician Dialect
The Hebrew Alphabet
Vowels in the Hebrew Alphabet
Hebrew Letters as Numbers
Writing The Lord's Name in Hebrew
Using a Word Processor with Hebrew
WWW and the Mark of the Beast?
Hebrew - The Holy Language
Hebrew and Yiddish