66706...01711 (232-digits)

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

                                                    66 7065556441 6328621661
0559955886 5778567155 6554605356 5253515150 5049504851 4753465645 6044654371
4278418640 9540053916 3828374136 5535703486 3403332132 4031603081 3003292628
5027752701 2628255624 8524152346 2278221121 4520802016 1953189118 3017701711

The largest prime formed from reverse concatenation of n consecutive 4-digit triangular numbers (n=58). [Gupta]