26162...51817 (40-digits)

This number is a prime.

                                 2616218222 8221436068 6456449363 5469851817

This prime can be written as the sum of squares of the first 21 factorials: (1!)^2 + (2!)^2 + (3!)^2 + (4!)^2 + (5!)^2 + (6!)^2 + (7!)^2 + (8!)^2 + (9!)^2 + (10!)^2 + (11!)^2 + (12!)^2 + (13!)^2 + (14!)^2 + (15!)^2 + (16!)^2 + (17!)^2 + (18!)^2 + (19!)^2 + (20!)^2 + (21!)^2. [Post]