5525
Smallest natural number that can be obtained as sum of two square numbers in six different ways:
5525 = 9^2 + 74^2 = 14^2 + 73^2 = 22^2 + 71^2 = 25^2 + 70^2 = 41^2 + 62^2 = 50^2 + 55^2
more interesting 4-digit numbers:
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