15013...50421 (69-digits)

This number is a prime.

 150131050 1404440344 2944308279 8310598637 9952297360 2358139554 7678450421

Smallest prime of the form sigma(1)^sigma(1) + sigma(2)^sigma(2) + ... + sigma(n)^sigma(n), (case n=21). [Sariyar]