prime number

noun

By · According to Wiktionary data (CC BY-SA) ·

"prime-number" is a 11-letter English headword indexed on PlainSpell.

The verdict

“prime number” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.

Unranked
below top-frequency English
12
letters

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Any natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers.

Key facts for prime number
PropertyValue
Headwordprime number
LanguageEnglish
Part of speechNoun
Letters12
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “prime number” sits in English frequency

prime number falls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

prime number is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. 2 senses are on record.

We couldn't generate a plausible misspelling set for prime number, which points to an orthography that plays by predictable English rules. We don't track a confusable pairing for this entry, which tends to mean the word is visually distinctive enough to stand on its own.

Our source data has no etymology on file for this entry, so its spelling is best explained by sound-to-letter mapping rather than etymology. The correct English form is prime number, spelled P-R-I-M-E- -N-U-M-B-E-R.

Definition

  1. 1
    Any natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers.
  2. 2
    Any natural number (including 1) that is divisible only by itself and 1.

Synonyms

prime

Antonyms

composite number

This word in other languages

número primo(Español)nombre premier(Français)Primzahl(Deutsch)

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "prime number"?
"prime number" is spelled P-R-I-M-E- -N-U-M-B-E-R.
What does "prime number" mean?
As a noun, "prime number" means: Any natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers.
What language does "prime number" come from?
"prime number" is a English word. PlainSpell's reference spans five languages -- English, Spanish, Portuguese, French, and German -- with definitions, pronunciations, and spelling data for each.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Using “prime number”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is P-R-I-M-E- -N-U-M-B-E-R - every other letter order is a misspelling in standard orthography.
  • Browse more English words and confusable pairs in the same reference. English words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list