479

479 is a prime number. Moreover, the differences between any two of its digits are also prime.

479 is a number that cannot be written as a sum of three squares.

479 is the largest known prime number that cannot be represented as the sum of fewer than nineteen fourth powers.

Inserting 0 between adjacent digits of 479 produces a prime: 40709.

479 is the telephone area code serving northwestern Arkansas.

Source: Prime Curios!