Sheldon TV why is 73 a cool number

On an episode of Sheldon he claims 73 is the best number. See it at:
https://www.bing.com/videos/search?q...E824&FORM=VIRE

Here is a spreadsheet showing first 1000 prime numbers and their Mirrored values. Then taken to Decimal and finally marked in yellow those that are palindromes.
Primes Mirrored and Binaried to Palindrome.xlsm

So the real problem here is:

Find a prime number whose binary equivalent is a palindrome AND whose Mirror decimal number converted to binary is also a palindrome. Is there such a number? What is the first one? (The first one is 3 and the second is 5 while 7 also fits the rules) Now can you find the next one greater than 7?

I also wonder why my Dec2Bin() function (in the attached workbook above) doesn't work on larger numbers.

I've discovered a better Dec2Bin UDF but now wonder if 313 is a possible answer to my problem? Can you test it? If 313 works can you find the next one?

Primes Mirrored and Binaried to Palindrome Wrong.xlsm