81180...21111 (235-digits)

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

                                                 81180 1791781771 7617517417
3172171170 1691681671 6616516416 3162161160 1591581571 5615515415 3152151150
1491481471 4614514414 3142141140 1391381371 3613513413 3132131130 1291281271
2612512412 3122121120 1191181171 1611511411 3112111110 1918171615 1413121111

+ The smallest prime formed by concatenating in reverse order the first n numbers that end with 1, (n=82), i.e., 811, 801, 791, ..., 101, 91, 81,…, 31, 21, 11, 1. [Loungrides]

Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell