2501

This number is a composite.

+ The product of the only two primes (41 and 61) that can be the last two digits of a perfect fourth power. If you replace the 5 by a 4, you get a fourth power (2401).

+ The smallest 4-digit Friedman brilliant number, i.e., 2501 = 50^2 + 1 = 41 x 61. [Loungrides]

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