Martin Raab has discovered a new first (and largest) known occurrence prime gap of measure G=6582144 following the 216841-digit prime P1=499973#/30030 - 4509212 (where 499973# indicates the product of all primes from 2 through 499973 inclusive).
This gap was first reported by Raab on 01 July 2017. The endpoints have passed the strong BPSW test (Nicely, 04 September 2017) for probabilistic primality.
A test for deterministic certification of primality is at present out of the question. The gap has merit M=13.182884.