"NICE" number?

Number Theory Level pending

A natural number is considered "NICE" if the product of all of its digits is larger than the number itself. How many 2018-digit numbers are there which are "NICE"?

Example: 50 is not a "NICE" number because the product of its digits, that is 0, is smaller than the number, 50, itself.


The answer is 0.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Kee Jerry
Jan 24, 2018

Consider a number with n-digits. Next, consider the first digit of the number and let it be x. Take an example that is 80, where n=2,x=8. Thus, in order the product of the digits to be larger than the original number, the product of the digits should be at least x*10^n, and it is impossible for that the value of a digit is larger than 9. And thus, a so described "NICE" number actually doesn't exist at all (no matter how many digit it is) and thus there is 0 "NICE" number within 2018-digit numbers.

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...