Problem 2491. Dudeney Numbers: Numbers which are the cube of their decimal sum

Created by Peter Cook

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","targetMode":"","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","targetMode":"","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>From Wikipedia: </w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:i/></w:rPr><w:t>A Dudeney number is a positive integer that is a perfect cube such that the sum of its decimal digits is equal to the cube root of the number.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>For example:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>512=(5+1+2)^3</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>4913=(4+9+1+3)^3</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>19683=(1+9+6+8+3)^3</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Write a function that returns true if a number is a Dudeney number and false otherwise.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Assume all numbers are of base 10.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>If a number is negative, assume that only the leading digit carries the negative sign e.g. -4913 -&gt; (-4+9+1+3)^3</w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

Solve

Solution Stats

117 Solutions
66 Solvers

Last Solution submitted on Aug 23, 2023

Last 200 Solutions

Problem Comments

2 Comments

2 Comments

Alex Drikitis on 14 Sep 2021

is there any negative dudeney number?

Dyuman Joshi on 14 Sep 2021

Depends upon how you define them.

If you are taking - sign outside the cube of the sum, every negative number corresponding to the positive Dudeney number is a Dudeney number.

If you define by the way OP has defined, -1 qualifies as a Dudeney number.

Solution Comments

Show comments

Problem Recent Solvers66

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 2491. Dudeney Numbers: Numbers which are the cube of their decimal sum

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers66

Suggested Problems

More from this Author9

Problem Tags

Community Treasure Hunt

Problem 2491. Dudeney Numbers: Numbers which are the cube of their decimal sum

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers66

Suggested Problems

More from this Author9

Problem Tags

Community Treasure Hunt

Players