4. Optimus Prime and Bumblebee set off from Earth and Cybertron simultaneously, heading towards each other. The speed ratio of Bumblebee to Optimus Prime is $4: 5$. One hour after they set off, Bumblebee encounters Megatron's interception and fights for half an hour. Then Bumblebee continues, but due to injuries, the speed is reduced by $25 \%$. When Bumblebee meets Optimus Prime, it is 22 minutes and 30 seconds later than the expected meeting time. If the meeting point of Bumblebee and Optimus Prime is 700,000 kilometers away from the midpoint between Earth and Cybertron, then the distance between Earth and Cybertron is $\qquad$ million kilometers.
$504$