Angela's suggestion of using the ItemType Definition Report is probably the best approach since it filters out all of the system properties that are automatically created. However if you need all of the properties on the ItemType, then you can use a query like the one below.
<Item type="ItemType" action="get" select="name" where="ItemType.name = 'Part'">
<Item type="Property" action="get" select="name,data_type"/>
Aras Labs Software Engineer
Yes, you can use the REST API to get this information just the same as you can with AML. I'd recommend checking out this blog post which covers a few examples of how to get item data using the REST API. In particular, I'd recommend checking out the Get relationships / related items section.