perplexus.info :: Numbers : From eleven to ... ETERNITY

Home > Numbers

From eleven to ... ETERNITY (Posted on 2018-07-14)

Eleven is the fifth prime number, and the smallest two-digit prime.
It's also the smallest repunit prime.

What is the next repunit prime?

See The Solution Submitted by Ady TZIDON

No Rating

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

save a bit of work

Comment 3 of 3 |

Every third repunit may be ignored as divisible by 3, since its digits sum to a number divisible by 3. Also, I wonder if all solutions have a prime number of digits...

Posted by Steven Lord on 2018-07-14 17:12:57

Please log in:

Login:
Password:
Remember me:

Sign up! \| Forgot password

Search:

Search body:

Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (5)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:


perplexus dot info