“73 is the 21st prime number. Its mirror, 37, is the 12th, and its mirror, 21, is the product of multiplying seven and three ... and in binary, 73 is a palindrome, 1001001, which backwards is 1001001.” 

Another great episode by @veritasium

“73 is the 21st prime number. Its mirror, 37, is the 12th, and its mirror, 21, is the product of multiplying seven and three ... and in binary, 73 is a palindrome, 1001001, which backwards is 1001001.” 

Another great episode by @veritasium 

https://youtu.be/d6iQrh2TK98?si=zZJyiCspoOoNSOOz