The Armstrong Number 153

153 is a narcissistic — or Armstrong — number: 1³ + 5³ + 3³ = 1 + 125 + 27 = 153. It equals the sum of the cubes of its own digits. Only four three-digit Armstrong numbers exist: 153, 370, 371, and 407. 153 is also the 17th triangular number (1 + 2 + … + 17 = 153) and appears in the New Testament: the disciples' miraculous catch was precisely 153 fish, which early Christian mathematicians noted with reverence. Whether the author knew the mathematics is unknown — but the number is remarkable either way.