perplexus.info :: Numbers : Tetra-productial numbers

Tetra-productial numbers (Posted on 2003-05-13)

Show that there are infinitely many integers n such that:

1) All digits of n in base 10 are strictly greater than 1.
2) If you take the product of any 4 digits of n, then it divides n.

See The Solution Submitted by Fernando

Rating: 2.2500 (4 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

A problem with that

| Comment 5 of 7 |

(In reply to re[fined]: Solution by DJ)

The problem there is 2222222 is not divisible by 2*2*2*2 or 16. You need the product of the 4 digits, not just the 4 digits in a row.

Posted by Gamer on 2003-05-14 12:24:45

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