Attempting to create a VM with more than 20 GB of Memory fails due to illegal memory size

Issue

When I attempt to create a VM via the Administrator Portal or via the API I am getting a message that states:

• API:

  [Cannot add VM. Illegal memory size is provided, size needs to be between 256 MB and 20480 MB.]

• UI: I manually enter a memory size of 123456 MB and press 'OK'. The Memory Size field is highlighted orange and when you hover over a message is displayed:

  Maximum memory size is 20480MB