3

The number 3, also called three, is very special. It is a numeral and a digit that comes after the number 2 and before the number 4. It is the smallest odd prime number and the only prime number that comes right before a square number.

Because of its unique qualities, the number 3 has deep meaning in many religions and cultures around the world. People have used this number in many important ways throughout history.

For technical reasons, the symbol ":3" leads to this page. If you are looking for keyboard symbols, you can find more information in the List of emoticons. The number 3 is linked to many ideas in math, such as being a natural number, a prime number, and more, including its role as a numeral and digit.

Evolution of the Arabic digit

The number 3 has been written in many different ways across various writing systems. Early forms, like those in Roman and Chinese numerals, used three lines. In ancient Indian scripts, such as the Brahmic system, the number 3 was also shown with three lines, but later changed during the Gupta Empire by adding curves to each line.

As these Indian digits spread to the Caliphate in the 9th century, they evolved further. In some areas, like the Maghreb and Al-Andalus, the bottom stroke was dropped, leading to the Western form of 3 we use today. In other regions, the stroke was kept and changed to create the modern Arabic digit "٣".

In most modern Western fonts, the digit 3 is about as tall as a capital letter and sits on the same line as other letters. Some special fonts make it shorter, fitting the height of a lowercase letter. There is also a special form of the digit 3 used to prevent forgery, often seen on things like UPC-A barcodes and standard 52-card decks.

Mathematics

The number 3 is very important in math. It is the smallest odd prime number and comes after 2 and before 4. One special rule is that a number is divisible by 3 if the sum of its digits is also divisible by 3. For example, 12 has digits 1 and 2, which add up to 3, so 12 can be divided by 3.

Triangles, which have three sides, are the simplest shapes with straight sides. The number 3 also appears in many math patterns and sequences. It is the smallest number that is both a prime and a triangular number.

Engineering

The triangle, a polygon with three edges and three vertices, is the most stable shape in nature. Because of this, it is often used in building, engineering, and design.

Three is also a special number in many stories and ideas around the world. Some people see it as a symbol of important things, like the idea of a lost place from old tales.

Religion and beliefs

See also: Triple deity

Many religions feature groups of three important ideas or gods. Examples include the Hindu Trimurti and Tridevi, the Triglav of the Slavs, the three Jewels in Buddhism, the three Pure Ones in Taoism, and the Christian Trinity.

In some cultures, the number three is seen as lucky. For example, in Chinese culture, it sounds similar to the word for "alive," making it a positive number. There is also a saying that “third time’s the charm,” meaning the third try is often successful. However, some believe that bad luck can also come in threes.