Numbers-------- — Badulla Badu

For example: Let ( N = 123 ). Digit sum = 6, reverse = 321, product ( 123 \times 321 = 39483 ), which is not a palindrome. So not a BBN.

Alternatively, the phrase could be a mishearing of "Badulla Badu" as "Buddhālaṅkāra" numbers—a lost Sinhala mathematical text. In modern number theory, newly defined sequences often find use in cryptography. If we define Badulla Badu Numbers as those that are both pseudoprime to base 2 and non-palindromic but become palindromic after reversing digits and multiplying by the original number’s digit sum, they could serve as keys in hash functions. Badulla Badu Numbers--------

Let’s instead define: are those that are not palindromes themselves, but become palindromes after exactly one reversal and addition, and the resulting palindrome has a digit sum that is a prime number. For example: Let ( N = 123 )

So a more refined requires the palindrome to be of odd length, or the reversal step itself to be non-trivial. Alternatively, the phrase could be a mishearing of