564

564 = 2² x 3 x 47.

564 is the largest number that can be written with all the digits from 1 to 5 (without repetition) as a sum of primes in two ways: 564 = 541 + 23 = 523 + 41.

The largest prime factor of F₁₁ (the largest completely factored Fermat number) has 564 digits.

564 is 202220 in base 3 and 4224 in base 5. It is 1434 in base 7 and 686 in base 9. It is 345 in base 13 and 234 in base 16.

Interstate 564 (I-564), known as Admiral Taussig Boulevard, runs east for 3.03 miles, providing access to Naval Station Norfolk in Virginia.

Source: Prime Curios!