Best number of world

The world's best number is 73 as

• 73 is 21^st prime number
• The number 21 = 7 X 3
• Binary representation of 21 is 10101 which is palindrome
• Its mirror is 37 which is also prime number. 37 is the 12^th prime number
• Binary representation of 73 is 1001001 which is palindrome