Prime Number with Prime Digits

  • Context: High School 
  • Thread starter Thread starter fibonacci235
  • Start date Start date
  • Tags Tags
    Prime
Click For Summary

Discussion Overview

The discussion revolves around the concept of prime numbers whose digits are all prime. Participants explore whether there is an established name for such numbers, the implications of number representation systems, and the relationship between digit properties and primality.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants inquire if there is a specific name for prime numbers whose digits are all prime, citing examples like 2, 3, 5, 7, and 23.
  • One participant argues that the property of a number being prime is independent of its representation system, suggesting that digit properties may not hold across different bases.
  • Another participant notes that while there are established names for various types of primes, such as Mersenne and palindromic primes, they are unsure if a name exists for primes with all prime digits.
  • Concerns are raised about the significance of naming such numbers, with a suggestion that the naming of palindromic numbers is due to their recognition outside of mathematics.
  • It is mentioned that in binary, if 1 is not considered prime, such numbers cannot exist, while larger bases allow for more prime digits.
  • One participant proposes the term "Digital Primes" for primes whose digits are all prime.

Areas of Agreement / Disagreement

Participants express differing views on the existence of a name for primes with all prime digits, with some suggesting that no such name is widely recognized, while others propose new terminology. The discussion remains unresolved regarding the significance and study of these numbers.

Contextual Notes

The discussion highlights the dependence of digit properties on the number representation system used, and the potential limitations in defining and categorizing such primes across different bases.

fibonacci235
Messages
15
Reaction score
1
Is there a name for a prime number whose digits are all prime? The first several that I can think of are

2,3,5,7 and 23, 23 being the first double digit prime whose digits are all prime.
 
Mathematics news on Phys.org
Well, I don't think so.
Reason?
It ought to be just an artefact of the particular number representation system you use.

If you let "11" be your base number, rather than 10, your "23" will be written as 21, the latter digit not being prime at all.

The quality of a number being prime is independent of its particular representation, but you can't expext the same for the digits of two distinct representations of the same number.
 
I know that a prime number doesn't depend on its representation, but number theorists have names for different types of primes i.e. Mersenne primes, Irregular primes, Safe primes, and my personal favorite, Sexy primes. I just wanted to know if there was a name for this particular type of prime. For example, as you probably well know there is a name for numbers like 222. They're called palindromic numbers. Now, 313 is a palindromic number but it is also prime. I know that 313 is prime independently of being a palindromic number. That's just a coincidence. My point is, is there a specific name for primes whose digits are all prime? That's all I'm getting at. This also raises the question, are there an infinite number of palindromic primes? Maybe, for the sake of precision, I should have posed my question this way: In a base 10 number system is there a name for a prime number whose digits are all prime?
 
Mersenne primes are Mersenne primes in all number systems, and so on.

Sure, some of dubbed palindromic numbers as being palindromic. But, just because you set a name on something doesn't mean it constitutes anything worthwhile studying (i.e, nobody studies palindromic numbers)

The reason why palindromic numbers have gotten their name is that the property of palindromy is well known outside maths, so it sort of stuck.

I would be extremely surprised if anyone has given your types of perfectly definable numbers a particular name (I'm not at all saying your question was vague or anything. It wasn't, your first post was perfectly clear)
 
If you count 1 as not being prime, then numbers of this type can't exist in binary. The larger your base is, the more such numbers can exist in that base, because you have more single digit primes. Example, in Hex, B and D are prime. (Funny, I always thought of them as being "even letters".)

This sounds like "Happy numbers" which are also base dependent.
 
arildno said:
Mersenne primes are Mersenne primes in all number systems, and so on.

Sure, some of dubbed palindromic numbers as being palindromic. But, just because you set a name on something doesn't mean it constitutes anything worthwhile studying (i.e, nobody studies palindromic numbers)

The reason why palindromic numbers have gotten their name is that the property of palindromy is well known outside maths, so it sort of stuck.

I would be extremely surprised if anyone has given your types of perfectly definable numbers a particular name (I'm not at all saying your question was vague or anything. It wasn't, your first post was perfectly clear)

Then I think I will name them Digital Primes.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 4 ·
Replies
4
Views
3K