This number is a prime.
The prime that needed the larger R for satisfying de Legendre's formula for the number of primes less than or equal to x; π(x) = x/(ln(x) - r). I.e., 24137 is the 2688th prime and that value is produced by the formula when r = 1.111963. No other prime needs so large an r for producing the true value of π(x) when any x is given. [Dusart]