- Wed Jun 25, 2025 1:53 pm#8734
23 | There Is Such Thing as Happy Numbers
You heard one is the loneliest number, but did you know numbers can be happy, too? To test if a number is "happy," replace it with the sum of squares in its digits, and continue the process until the number equals 1, or loops into a cycle that does not include 1. If the process ends with 1, the number is happy. For example, take 23:
22 + 32= 13
12 + 32 = 10
12 + 02 = 1
That means 23 is a happy number! Counting to 1,000, you'll find there are 143 hap-py numbers.
24 | 7 Is Arithmetically Unique
The number 7 may be so popular because it is arithmetically unique. Alex Bellos, again, explains: "Of the first 10 numbers, seven is the most prime. You cannot multiply or divide it within the group. It feels unique." For example, you could multiply 4 by 2 to get 8 or divide 10 by 2 to get 5, but there's nothing you can do with 7.
25 | India's National Game Means "Twenty-Five"
The cross-and-circle board game of Pachisi is a hugely popular game in India dating back centuries, played on a board in which a player throws several cowry shells. Its name translates in Hindi to "Twenty-Five," which refers to the largest score that can be earned through the toss of the shells (there's also a version where the score can reach 30).
26 | Six Weeks = 10! Seconds
That is, 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 = 3,628,800 seconds = 60,480 minutes = 1,008 hours = 42 days = 6 weeks.
27 | There's Not Enough Room in the World to Write Out a Googolplex
A googol means 1 followed by 100 zeroes. A googolplex is 1 followed by a googol zeroes. If it's hard to imagine how long that number would look, there's good reason for that: to write it out would create a number that's so huge, if you wrote it out and printed it in a volumed series of books, it would weigh more than the entire planet.
28 | The Mile-High City Is Exactly One Mile High
The city of Denver, Colorado, has an elevation of precisely 5,280 feet—that's the length of a mile—which is why Denver is called the "mile high" city.
29 | In Asia, 4 Is Considered Unlucky
Also known as "tetraphobia" the number 4 is viewed with superstition and distrust in much of East Asia. The reason for this may be due to the fact that the word for "four" sounds similar to "death" in a number of Asian languages, including Chinese, Japanese, and Korean.
30 | In Thailand, "555" Is Hilarious
Teenagers texting in Thailand (say that three times fast) will send the digits "555" to indicate that something is funny. The reason? "5" is pronounced "ha"—so "555" translates to "hahaha." Thus, "55555" means "hahahahaha," or "ha" squared.
You heard one is the loneliest number, but did you know numbers can be happy, too? To test if a number is "happy," replace it with the sum of squares in its digits, and continue the process until the number equals 1, or loops into a cycle that does not include 1. If the process ends with 1, the number is happy. For example, take 23:
22 + 32= 13
12 + 32 = 10
12 + 02 = 1
That means 23 is a happy number! Counting to 1,000, you'll find there are 143 hap-py numbers.
24 | 7 Is Arithmetically Unique
The number 7 may be so popular because it is arithmetically unique. Alex Bellos, again, explains: "Of the first 10 numbers, seven is the most prime. You cannot multiply or divide it within the group. It feels unique." For example, you could multiply 4 by 2 to get 8 or divide 10 by 2 to get 5, but there's nothing you can do with 7.
25 | India's National Game Means "Twenty-Five"
The cross-and-circle board game of Pachisi is a hugely popular game in India dating back centuries, played on a board in which a player throws several cowry shells. Its name translates in Hindi to "Twenty-Five," which refers to the largest score that can be earned through the toss of the shells (there's also a version where the score can reach 30).
26 | Six Weeks = 10! Seconds
That is, 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 = 3,628,800 seconds = 60,480 minutes = 1,008 hours = 42 days = 6 weeks.
27 | There's Not Enough Room in the World to Write Out a Googolplex
A googol means 1 followed by 100 zeroes. A googolplex is 1 followed by a googol zeroes. If it's hard to imagine how long that number would look, there's good reason for that: to write it out would create a number that's so huge, if you wrote it out and printed it in a volumed series of books, it would weigh more than the entire planet.
28 | The Mile-High City Is Exactly One Mile High
The city of Denver, Colorado, has an elevation of precisely 5,280 feet—that's the length of a mile—which is why Denver is called the "mile high" city.
29 | In Asia, 4 Is Considered Unlucky
Also known as "tetraphobia" the number 4 is viewed with superstition and distrust in much of East Asia. The reason for this may be due to the fact that the word for "four" sounds similar to "death" in a number of Asian languages, including Chinese, Japanese, and Korean.
30 | In Thailand, "555" Is Hilarious
Teenagers texting in Thailand (say that three times fast) will send the digits "555" to indicate that something is funny. The reason? "5" is pronounced "ha"—so "555" translates to "hahaha." Thus, "55555" means "hahahahaha," or "ha" squared.
