The number traditionally considered unlucky in many cultures is 13. This superstition, known as triskaidekaphobia, is widespread in various societies and can be traced back to different historical and mythological sources. For example, in Christian traditions, there were 13 individuals present at the Last Supper, leading to the belief that having 13 people at a table brings misfortune. In some cultures, Friday the 13th is deemed especially ominous. As a result, many buildings skip labeling the 13th floor, and some airlines avoid having 13 seats in their rows. Despite these beliefs, others consider the number 13 to be lucky, highlighting its cultural variability.