## Difference of two squares

(I saw this post from six years ago, barely a month after I published 25 Math Short Cuts. This may partly explain how my first printing of 3,500 was sold out in one month). A sponsored post by Brilliant.org asks…

“2021 is a product of two consecutive prime numbers.: 2021 =43 x 47 Further, 2021 produces a palindrome when multiplied by its reverse. A palindrome is number which remains the same even when its digits are written in reverse order:…