While @Flores's answer pointed me in the right direction, he did not do what was expected. At least I still had commas in my filter using its fragment. As a result, I made a small modification of the code to achieve the desired result.
filterable: { ui: function (element) { element.kendoNumericTextBox({ format: '#', decimals: 0, }); }, },
This will give you only numbers. No commas or decimals.
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