AngularJS Example:

HTML

<div ng-app>
  <div ng-controller="TodoCtrl">
      <input type="number" ng-model="value"  size="30" id='mynumber'>
      <input type="button" ng-click="change()" class="btn-primary" value="TEST" >
  </div>
</div>

JavaScript

function TodoCtrl($scope) {
  $scope.change = function() {
  	if (!document.getElementById('mynumber').validity.valid)
    {
    	$scope.value = null
      document.getElementById('mynumber').value='';
    }
    
  }
}