This number is a composite.
8499, all 4 of whose digits are prime powers, is the sum of the squares of 3 consecutive primes: 47^2 + 53^2 + 59^2. [Post]
8499, all 4 of whose digits are prime powers, is the sum of
the squares of 3 consecutive primes: 47^2 + 53^2 + 59^2. [Post]