# 457

This number is a prime. The German submarine known as U-457 was sunk in the Barents Sea by depth charges from the British destroyer HMS Impulsive during WWII. [Wynn] The first Honaker prime (p88 = 457: 8+8 = 4+5+7) that is itself the subscript of another Honaker prime (p457 = 3229: 4+5+7 = 3+2+2+9). [Beedassy] The Amazon Standard Identification Number (ASIN) for Nate Kenyon's science fiction novel "Prime" is B00457XFFQ. [Sardina] If the symbols of Z340 are translated to a numeric form, where each unique symbol is assigned a unique number, then the sum of only one row (the 18th) is prime, i.e., 19 + 19 + 33 + 26 + 56 + 40 + 26 + 36 + 9 + 23 + 42 + 1 + 14 + 54 + 21 + 33 + 5 = 457. [Honaker] A cycle of four year (three non-leap and one leap) has 457 prime days. [Post] Is 457 the only Honaker prime for which its prime index (88) plus 666 is an anagram of the prime? [Gaydos] The smallest prime number for which the reverse of its double is a smaller prime. [Gaydos] The 457th Fibonacci number is a 96-digit number containing the digit 2 just once. Is this the largest Fibonacci number that has one or more unique digits? [Gaydos] The concatenation of the three values of n for which (n!+1) is a perfect square. [Kilpatrick] There are 457 squares that are each the sum of two consecutive distinct digit positive integers. [Gaydos] The first Honaker prime with a repdigit prime index (88). [Gaydos] The smallest Honaker prime that is the hypotenuse of a Pythagorean triangle: {457, 425, 168}. [Bajpai]

(There is one curio for this number that has not yet been approved by an editor.)