prime number

American  

noun

Mathematics.

• prime numbers
  plural

1. a positive integer that is not divisible without remainder by any integer except itself and 1, with 1 often excluded.

   The integers 2, 3, 5, and 7 are prime numbers.

---

prime number British  

noun

1. Sometimes shortened to: prime. an integer that cannot be factorized into other integers but is only divisible by itself or 1, such as 2, 3, 5, 7, and 11 Compare composite number

---

prime number Scientific  

1. A positive integer greater than 1 that can only be divided by itself and 1 without leaving a remainder. Examples of prime numbers are 7, 23, and 67.

2. Compare composite number

---

prime number Cultural  

1. A number that cannot be divided evenly by any other number except itself and the number one; 1, 3, 5, 7, and 11 are prime numbers.

---

Other Word Forms

Noun Inflected Forms

• prime numbers
  plural

---

Etymology

Origin of prime number

First recorded in 1585–95

---

Example Sentences

See Examples For:

prime number

Six is a perfect number, and seven is a prime number, but only a glutton for punishment would put them together in front of a bunch of 13-year-olds.

From The Wall Street Journal ● Oct. 14, 2025

“It’s like an entire alien species living underneath our feet and then some prime number years they come out to say hello.”

From Seattle Times ● Apr. 1, 2024

Sixty-one is a prime number, just as the Slate News Quiz is a prime example of good quizzing fun.

From Slate ● Oct. 7, 2022

After an initial transmission of a prime number to mark the message as artificial, Jiang’s message uses the same alien alphabet to introduce our base-10 numeral system and basic mathematics.

From Scientific American ● Mar. 30, 2022

A prime number is a number that can only be divided by itself and one.

From "The Lions of Little Rock" by Kristin Levine

Random Word

Spin the wheel and learn a new word!

---