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prime number

American  

noun

Mathematics.
  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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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.


Etymology

Origin of prime number

First recorded in 1585–95

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

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

But, as the official synopsis says, “finding a pattern in prime numbers … would allow him to access every computer in the world.”

From Los Angeles Times

“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

Do they become rarer with increasing size, like the prime numbers, or do they always appear with about the same frequency?

From Scientific American

She looked intrigued, which was new, because Katie usually walks around with this distracted expression on her face, like she’s busy figuring the square root of the prime number closest to the gross national product.

From Literature