A number's persistence is the number of steps required to reduce it to a single digit by multiplying all its digits to obtain a second number, then multiplying all the digits of that number to obtain a third number, and so on until a one-digit number is obtained.
For example, 66 has a persistence of three because it requires three steps to reduce it to one digit: 66-36-18-8.
Solution Stats
Problem Comments
Solution Comments
-
1 Comment
James
on 22 Nov 2013
*smacks forehead* Recursion makes a lot of sense here. Wish I had thought of it...
Recent Solvers56
Suggested Problems
-
2076 Solvers
-
234 Solvers
-
Find a subset that divides the vector into equal halves
278 Solvers
-
186 Solvers
-
236 Solvers
More from this Author13
Tags
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
Select web siteYou can also select a web site from the following list:
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)