
Curios:
Curios Search:
Participate: 
A palindromic prime formed from the first five digits, where each digit d is repeated d times in ascending and descending order. [Silva] This palindromic prime of 5by5 digits consists of five 5's, surrounded on each side by four 4's, three 3's, two 2's and one 1. (The only other similar prime is 122333221.) [Hasler] This prime can take a pyramidal form whose base is a palindrome with the first five digits: 5 454 34543 2345432 123454321. [Silva]
Prime Curios! © 20002018 (all rights
reserved)
