19898...89891 (157-digits)

This number is a probable-prime (likely to be a prime but we have not (re-)proven it on this site).

1989893 9319514516
8117180173 1111833581 1014734515 7137138109 1081041211 2512110210 0300120112
1521121401 8019018317 3175154374 1011853381 1113710817 1186154159 1393989891

Single Curio View: (Seek other curios for this number)

The bottom row of a palindromic prime pyramid of odd primes (starting with 3) of step size 3 and height 27, where each palindromic prime p is the smallest p containing p in the above row. [Gupta]

Submitted: 2024-08-26 02:44:09; Last Modified: 2025-10-01 01:16:09.