Word Pronunciation & Dictionary

happy number

Word Rarity Common

Frequency: Zipf frequency 5.16 in modern English

Syllables: hap-py num-ber
IPA

25

Scrabble Score

11

Letters

3

Syllables

10

Unique Chars

Meaning

noun

Any number that eventually reaches 1 after some number of iterations of replacing each of its digits by the sum of that digit's squares.

Example Sentences

"13 is a happy number because 1² + 3² is 10, and 1² + 0² is 1."

Etymology

Popularised by the British mathematician Reginald Allenby in the 1960s, who developed this concept from his daughter, while similar mathematical formulas may have existed earlier in Russia. The number was called "happy" because the iteration to reach 1 was treated like a game of numbers, where reaching 1 is compared to "winning" that game.

Inflected Forms

happy numbers (plural)

Antonyms

sad number unhappy number

Questions

What does happy number mean?: Any number that eventually reaches 1 after some number of iterations of replacing each of its digits by the sum of that digit's squares.
Where does happy number come from?: Popularised by the British mathematician Reginald Allenby in the 1960s, who developed this concept from his daughter, while similar mathematical formulas may have existed earlier in Russia. The number was called "happy" because the iteration to reach 1 was treated like a game of numbers, where reaching 1 is compared to "winning" that game.

How to pronounce happy number

Open the pronunciation page — Open the Speakur entry for “happy number”.
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