I bet you're right. I wonder if Rowling put them in or the developer? Before, I just suspected that they were house numbers or birthdays of someone Rowling knew. If they're both prime numbers, that suggests someone with a mathematical mind came up with them. I think it's supposed to LOOK like a power meter. Where do British houses usually keep the power meter?
I've got early access, and the Gateway is the main Pottermore page after you log in. It's the gate image from the trailer with the paper cutouts and provides quick links to each book and each chapter of each book.
When I try to put either 1531 or 4157 at the end of the pottermore url, it directs me to the "sorry, this page has vanished" message telling me to go back to the Gateway.
My Wand Shop in Diagon Alley will reopen in November. In the meantime, check it out here!
Looks like I got too excited... if you type pottermore.com/somethingrandom it goes to the homepage, but if you type www.pottermore.com/somethingrandom it goes to the error page, so when I saw that 1457 took me somewhere different I thought it meant something...sorry about that
1+5+3+1 = 10 4+1+5+7 = 17 17-10=7 Also, the series began when Harry was 10 and ended when he was 17... I don't know if this means anything, or not. (I was thinking of Arithmancy when I decided to add everything, so if you continue with that... 1+0=1 and 1+7=8, 8-1=7)
I typed on my phone 2626 (4157-1531), 5688 (4157+1531) and 6364367 (4157x1531) and got these words: Coco, Knut and Members. I searched for Knut but found nothing and I'm not sure about coco (it wasn't in the kitchen) and really don't know which members are they mean.
Someone said that, if you have 3 cauldrons, you can type this at the end of the url when you're brewing a potion and be able to brew 3 potions at a time, but I'm suspicious of this and no one has tried it yet, to my knowledge.