Currently the set_value() method of the RadNumericTextBox throws an exception if null is passed to it as value while having the AllowOutOfRangeAutoCorrect property is set to true. This does not happen if the AllowOutOfRangeAutoCorrect is left as default (false).

Rad Numeric Text Box does react to the culture's group and decimal separator. But it does not react to the number format of the current thread's culture; instead always displays in million format. Enabling that will allow us to display display values in format other than the million format. 

Rad grid column does react to the number format.

MaxValue property is set to use the maximum value of int64: 9223372036854775807

Original value introduced is: 545445456456465454

Value becomes:  545445456456465000