Lychrel number

noun

A natural number that cannot form a palindrome through the iterative process of repeatedly reversing its digits and adding the resulting numbers.

“In base ten (decimal), no Lychrel numbers have been yet proved to exist, but many are suspected.”

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Meanings

nounLychrel number (plural Lychrel numbers)

plural Lychrel numbers

  1. mathematicsA natural number that cannot form a palindrome through the iterative process of repeatedly reversing its digits and adding the resulting numbers.

    In base ten (decimal), no Lychrel numbers have been yet proved to exist, but many are suspected.

Origin

Coined by Wade Van Landingham as a rough anagram of Cheryl, his girlfriend's first name.

Full word history & related roots →
Cite this entry
APA

Lychrel number. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Lychrel%20number

MLA

“Lychrel number.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Lychrel%20number. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “Lychrel number,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Lychrel%20number.

Source: Lychrel number on Wiktionary, CC BY-SA 4.0.