210

This number is a composite.

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 π(n - 2) - π(n/2 - 1) distinct ways. Reference: An upper bound in Goldbach's problem. [Capelle]