Special whole numbers...

[mart_r]

Originally Posted by Dr Sardonicus

the smallest gap size (difference of consecutive primes) whose first occurrence is not yet definitely known.

Perfectly correct!

Still don't have a clue regarding 20287, I'm afraid. Maybe tomorrow I wake up shouting "Heureka!"...

[tuckerkao]

Originally Posted by mart_r

Perfectly correct!

Still don't have a clue regarding 20287, I'm afraid. Maybe tomorrow I wake up shouting "Heureka!"...

I prefer 20736 because it's the whole power of something fundamental.

[R2357]

I saw 48 a bit above,
Possible Prime Positions for 7#




New number 987654103

[Viliam Furik]

Originally Posted by R2357

I saw 48 a bit above,
Possible Prime Positions for 7#




New number 987654103

Something in the sense of: Biggest prime containing unique decimal digits.

Such number can't contain all the digits because then it would be multiple of 9.

[R2357]

Yes, that's right!

[R2357]

I forgot to post the next number :

30 031

[Dr Sardonicus]

Originally Posted by Dr Sardonicus

I came up with the following number when musing about a recent announcement:

20287

The time has come. The "recent announcement" was that Amazon Prime Day would be October 13-14 this year. I wondered about associating either day with a prime number in some way.

Of course, the day-of-month 13 is prime. But I wondered if there was a way to associate either complete date, October 13 or 14, 2020, with a prime number.

And lo and behold, the Julian Date of October 13, 2020 is 20287. And 20287 is a prime number.

[retina]

Originally Posted by Dr Sardonicus

... the Julian Date of October 13, 2020 is 20287.

WP disagrees. It isn't even close.

[Dr Sardonicus]

Originally Posted by retina

WP disagrees. It isn't even close.

The term "Julian Date" (as opposed to Julian Day) is commonly used to mean the ordinal date, or day number in the current year. The day number of October 13 this year (a leap year) is 287. Prepending the last two digits of the year number gives the "Julian Date" in YYDDD format, here, 20287. Another common format is YYYY-DDD.

The Julian Day (number) is the number of days (including fractional part) since the beginning of the "Julian period" which is (12:00) January 1, 4713 BC, somewhat over 6000 years ago. The number of days in 6000 years is a bit larger than 6000x360 = 2160000. The Julian Day Number for (00:00) October 13, 2020 is 2459135.5 (nearest primes 2459129 and 245941).

There is also a "Modified Julian Day Number," which subtracts 2,400,000.5 from the Julian Day Number, shifting the starting date to November 17, 1858 and the start time from Noon to Midnight.

The Modified Julian Day Number for (00:00) October 13, 2020 is 59135 (nearest primes 59123 and 59141).

[R2357]

I thought this thread was about finding particularities in the posted number and post a number...

[retina]

Originally Posted by R2357

I thought this thread was about finding particularities in the posted number and post a number...

Okay. Here is a number: 314159265