Prime Cell Phone Numbers: Oddity or Probability?

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The discussion centers around the intriguing notion of prime phone numbers, sparked by the discovery of a ten-digit prime phone number. Participants explore the concept of prime numbers, sharing personal experiences with their own numbers and discussing the mathematical probability of ten-digit numbers being prime. The probability is estimated to be around 4.042% based on the distribution of primes, with approximately 404,204,977 ten-digit prime numbers identified. The conversation also touches on the mathematical properties of numbers, such as the fact that no even number can be prime, and the implications of phone number formatting rules that affect valid combinations. Various methods for checking the primality of numbers are suggested, including generating random numbers and using online tools or programming scripts. The thread reflects a mix of mathematical curiosity and light-hearted banter, with participants sharing their thoughts on primes and personal anecdotes related to numbers.
  • #31
Char. Limit said:
Except I don't live in Canada...

Its not nice tricking people into thinking that you live in Canada.
 
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  • #32
Tangentially related: both my birthday and month of birth are prime and together they form a http://en.wikipedia.org/wiki/Sexy_prime" pair. Yay.

None of my phone numbers are prime though.
 
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  • #33
Vasara said:
Tangentially related: both my birthday and month of birth are prime and together they form a http://en.wikipedia.org/wiki/Sexy_prime" pair.

May 11th, July 13th, November 5th, or November 17th, then.
 
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  • #34
Kajahtava said:
Okay, I've got an algorithm running right now which should give me the amount of ten digit primes, if anyone has a faster computer than I and runs scheme, or has some pointers on reducing complexity:

http://codepad.org/pD8jMxnp

I have no idea how long this will take, I made the algorithm to compute the list of primes a while ago, hence it has comments. In theory it should compute a list of all primes smaller than 999999999 and then count the the amount that are higher than 1000000000.

I have that number already -- 404204977. But I don't have the number that excludes area codes starting with 1, certain numbers with connection 555, etc.

Borek said:
7 = (\sqrt 7)^2

so 7 is a square.

"Square" is surely used in its number theory sense here, as Kajahtava suggests.
 
  • #35
What if where you live they don't have 10 digit phone numbers?
Well anyway, this 8 digit number of mine is even so... I'm one of the special ones that has a composite phone number.
 
  • #36
When did I say I was in Canada?

I've aleady mentioned in the Member Photo Thread that the lake behind me was Lake Coeur d'Alene... in Idaho.
 
  • #37
CRGreathouse said:
I have that number already -- 404204977. But I don't have the number that excludes area codes starting with 1, certain numbers with connection 555, etc.
Ah yes, good point.
"Square" is surely used in its number theory sense here, as Kajahtava suggests.
Even better point.
 
  • #38
Char. Limit said:
When did I say I was in Canada?

I've aleady mentioned in the Member Photo Thread that the lake behind me was Lake Coeur d'Alene... in Idaho.
If you don't remember I'm not going to remind you.





;-p
 
  • #39
Don't forget also, all numbers with the fourth through sixth digits "911" have to mostly cancel as well...
 
  • #40
CRGreathouse said:
May 11th, July 13th, November 5th, or November 17th, then.
Yup, November 5th is right. That's also the smallest sexy prime pair.
 
  • #41
Char. Limit said:
Don't forget also, all numbers with the fourth through sixth digits "911" have to mostly cancel as well...

I hadn't thought of that -- I wonder if this means the number I gave was too high, or if that rule is subsumed in another.

Vasara said:
Yup, November 5th is right. That's also the smallest sexy prime pair.

The 5th of November? Ominous.
 

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