424 has a representation as a sum of two squares: 424 = 102 + 182.
424 is 1144 in base 7 and 224 in base 14.
424 is the sum of ten consecutive primes: 424 = 23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61.
On April 10, 1941, USS Niblack (DD 424) used depth charges against a German U-boat while conducing rescue operations of a torpedoed Dutch freighter. This was the first action taken by a U.S. naval vessel against the Axis Powers.