Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
How many city/municipalties have an area (km2) of 506.64?

### Inputs:
table_name: table, columns: ['City / Municipality', 'Date of Creation', 'Area (km 2 )', 'Population (2010)', 'Income Classification ( DOF )']

### Response:
SELECT COUNT City / Municipality FROM table WHERE Area (km 2 ) = 506.64