Here’s a neat number curiosity that you may find interesting.

Choose any number (preferably, a larger one). For example,

5470315986321981423

Write down the number of even digits, odd digits and the number of digits of the number you selected respectively:

8 11 19

Concatenate the three numbers:

81119

Perform the procedure described above to the concatenated number:

81119

1 4 5

145

Do it once again:

145

1 2 3

123

Now, if you do it again, it’ll loop back to 123. Hence, you will end up getting 123 regardless of which number you start with.

### Like this:

Like Loading...

*Related*

So cool! One more reason to love math.

LikeLiked by 1 person

:)

LikeLike

So very cool!

LikeLiked by 1 person

Cool!

LikeLiked by 1 person

Thanks :)

LikeLike

I do wish I’d known you back when I taught mathematics to Middle school recalcitrants. Back then the only fun fact was talking about Fibonacci numbers.

LikeLiked by 1 person

:)

Fibonacci sequence is a great topic.

LikeLiked by 1 person

And it works well in Art, Science, Maths and Magic.

LikeLike

Edmark, you are toying with our minds. Never the less, I like it and say 1, 2,3, time to go.

LikeLiked by 1 person

Superb serendipity 🙂

LikeLiked by 1 person

Similar to what I’ve said before this is a curiosity but so is the who and why of its discovery.

LikeLiked by 1 person

I found this one by accident while tinkering with another number trick (of which I read from one of Martin Gardner’s books). This one is so trivial so I suppose that somebody had already discovered it before I did. I am now very careful at claiming a discovery after I foolishly thought that I “discovered” the Kaprekar’s constant when I was a teen. The disappointment was real when I learned that it was already discovered half a century ago :D

LikeLiked by 1 person

Scratching my head….will have to play with this to see it for myself…because in the words of a child I heard recently…”How do it know?”

LikeLiked by 1 person

Amazing number curiosity! I would love to see an explanation. Happy new year!

LikeLiked by 1 person

Here’s an easy explanation:

“Write down the number of even digits, odd digits and the number of digits of the number you selected respectively.”

The explanation lies here.

123 has one even digit, 2 odd digts and 3 digits in that order. This is the only number that meets the criteria. So, it doesn’t matter which number you choose, it will eventually reach 123 as there’s only one solution (123).

Once you reached 123, it’ll just loop back to 123 if you do the process again.

LikeLiked by 4 people

Thank for taking the time to explain!

LikeLike

Thank you for the follow Edmark. I look forward to reading more of your blog through this connection. 🙂

LikeLiked by 1 person

:)

LikeLiked by 1 person

May I just getch my dictionary first … (love a new word; concatenate) !!

Now I shalt do the number thing – I always loved number games!!

LikeLiked by 1 person

Glad you liked it :)

Concatenate is a common word in number theory so I forgot that it’s not commonly used :D The word is quite handy though :).

LikeLiked by 1 person

I love that you used it.

Your extra knowledge is shared and ours to accept and bank. If I may …. (oh, sorry, I already have!) :))

LikeLiked by 1 person

Amazing!

LikeLike

Season’s Greetings! ❄️🌲

LikeLiked by 1 person

Thanks, same to you. :)

LikeLike