Discovery of one 23-Digit Palindromic Prime in the Decimal Expansion of π

On January 16, 2026, a computational search was conducted to identify palindromic prime numbers of length 23 within the 25.9 × 1 0 12 − 26 × 1 0 12 - decimal digits of the mathematical constant π (approximately 3.141592653589793238462643383...). Using a modified C program with streaming capabilities to handle a 100 GB file containing the decimal expansion of π , one palindromic prime were discovered. A palindromic prime is a number that is both a palindrome (reads the same forwards and backwards) and a prime number. This document presents the positions of this palindrome in the decimal expansion of π . The detailed results, including certificate of primality and a confirmation of the absolute position using y-cruncher DigitViewer, are available on ZENODO