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You might be thinking why am I writing about an individual number? Actually, in previous year annual exams, my registration number was 381654729. Which is just an ‘ordinary’ 9-digit long number. I never cared about it- and forgot it after exam results were announced. But today morning, when I opened “Mathematics Today” magazine’s October 2010, page 8; I was brilliantly shocked. 381654729 is a nine digit number with each of the digits from 1 to 9 appearing once. The whole number is divisible by 9. If you remove the right-most digit, the remaining eight-digit number is divisible by 8. Again removing the next-right-most digit leaves a seven-digit number that is divisible by 7. Similarly, removing next-rightmost digit leaves a six-digit number that is divisible by 6. This property continues all the way down to one digit.
Further research on this number provided a term for this number as Poly-divisible Number.
And I also noticed that a similar problem has been asked in U S A Mathematical Talent Search competition. See the first question in the doc below:
To view this document in appropriate size click on View tab of the doc.
After this beautiful incident, I would like to quote a statement here:
Mathematical Wonders happen with Mathematicians.
Numbers always chase me.
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- Two Interesting Math Problems (wpgaurav.wordpress.com)
[...] thing from the blog of my friend, Gaurav Tiwari. So I’m just giving the link to his post : 381654729 : An Interesting Number Happened To Me Today/ The post is about the interesting facts about the number 381654729. Its real cool one!! Share [...]
Yes
mathematical wonders happen to mathematicians!!
Hey Gaurav, do you know the trick with 526315789473684210?
Not really, but what ever I know is that a part of above given ‘full reptended’ number always appear in the results.
[...] entrada me la sugirió este post del blog de Gaurav Tiwari. MeneameDivúlgameDivobloggerBitacorasDeliciousGoogle BuzzFacebookTwitter Download as [...]