
Some numerologists and New Age believers trust that events linked to the time 11:11 appear more often than can be explained by chance or coincidence, and this is an example of synchronicity. For such people seeing 11:11 on a clock has been claimed as an auspicious sign or signaling a spirit presence. Post-hoc reasoning and confirmation bias provides a context for such claims, and skeptics have pointed out that the assertions of people like Uri Geller that 11:11 is somehow important in world events do not hold up to even cursory scrutiny.

Heptadecaphobia or heptadekaphobia is the fear of the number 17. It is considered to be ill-fated in Italy and other countries of Greek and Latin origins, while the date Friday the 17th is considered especially unfortunate in Italy. The number is feared due to superstition, and is similar in nature to the fear of the number 13 in Anglo-Saxon countries.

"Four Eleven Forty-Four", or "4-11-44" is a phrase that has been used repeatedly in popular music and as a reference to numbers allegedly chosen by poor African Americans for the purpose of gambling on lotteries. It was a well-known phrase in the 19th and early 20th century in the United States.

Friday the 13th is considered an unlucky day in Western superstition. It occurs when the 13th day of the month in the Gregorian calendar falls on a Friday, which happens at least once every year but can occur up to three times in the same year. For example, 2015 had a Friday the 13th in February, March, and November; 2017 through 2020 had two Friday the 13ths each; and the years 2021 and 2022 will both have just one occurrence each.

The number of the beast is associated with the Beast of Revelation in chapter 13, verse 18 of Book of Revelation. In most manuscripts of the New Testament and in English translations of the Bible, the number of the beast is six hundred and sixty-six or χξϛ. Papyrus 115, as well as other ancient sources like Codex Ephraemi Rescriptus, give the number of the beast as χιϛ or χιϲ, not 666; critical editions of the Greek text, such as the Novum Testamentum Graece, note 616 as a variant.

The number of the beast is associated with the Beast of Revelation in chapter 13, verse 18 of Book of Revelation. In most manuscripts of the New Testament and in English translations of the Bible, the number of the beast is six hundred and sixty-six or χξϛ. Papyrus 115, as well as other ancient sources like Codex Ephraemi Rescriptus, give the number of the beast as χιϛ or χιϲ, not 666; critical editions of the Greek text, such as the Novum Testamentum Graece, note 616 as a variant.

The Number 23 is a 2007 American thriller film written by Fernley Phillips and directed by Joel Schumacher. Jim Carrey stars as a man who becomes obsessed with the 23 enigma once he reads about it in a strange book that seemingly mirrors his own life. The film was released in the United States on February 23, 2007. This is the second film to pair Schumacher and Carrey, the first being Batman Forever. The film grossed $77.6 million, and has an approval rating of 8% on Rotten Tomatoes.

Tetraphobia is the practice of avoiding instances of the digit 4. It is a superstition most common in East Asian nations.

Triskaidekaphobia is fear or avoidance of the number 13. It is also a reason for the fear of Friday the 13th, called paraskevidekatriaphobia or friggatriskaidekaphobia.

Friday the 13th is considered an unlucky day in Western superstition. It occurs when the 13th day of the month in the Gregorian calendar falls on a Friday, which happens at least once every year but can occur up to three times in the same year. For example, 2015 had a Friday the 13th in February, March, and November; 2017 through 2020 had two Friday the 13ths each; and the years 2021 and 2022 will both have just one occurrence each.