[ *August 12, 1999* ] *Palindrome* ** 21312 ** is another unique one

when taken into consideration the following two rules :

__First__, the digit zero may not appear in the palindrome

__Secondly__, the sum of its digits equals the number of its prime factors

**21312** = 2 + 1 + 3 + 1 + 2 = 9 so there should exist nine prime factors !

Indeed as **21312** = 2 x 2 x 2 x 2 x 2 x 2 x 3 x 3 x 37.

Dear puzzlers, proof me wrong by finding a second solution...

__P.S.__ **21312** is also the largest substring in **2**^{49} or **562949953421312** ( A046260 )

(Note for the insiders : **21312** equals **32** times the number of the beast **666**!)