210 (another Prime Pages' Curiosity)
 Curios: Curios Search:   Participate: The primes 47, 257, 467, 677, 887, 1097 and 1307 constitute a progression of 7 terms with a common difference of 210. [Barrow , Bush and Taylor] 210 is the smallest number with 4 distinct prime divisors. The largest single-digit primorial value, 7# = 2 * 3 * 5 * 7 = 210. [Nicholson] It has been estimated that 210 becomes a "jumping champion" at around 10^425. (21, 20, 29) and (35, 12, 37) are the two least primitive Pythagorean triangles with different hypotenuses and the same area (=210). [Sierpinski] The number of distinct representations of a number n as the sum of two primes is at most the number of primes in the interval [n/2, n-2], and 210 is the largest value of n for which this upper bound is attained. In other words, 210 is the largest positive integer n that can be written as the sum of two primes in (n - 2) - (n/2 - 1) distinct ways. Reference: An upper bound in Goldbach's problem. [Capelle]   To link to this page use http://primes.utm.edu/curios/page.php?number_id=49 Prime Curios! © 1999-2013 (all rights reserved)