2.1×1.1×0.54÷(5.4×1.21÷521)=______.

2.1×1.1×0.54÷(5.4×1.21÷521)=______.

2.1×1.1×0.54÷(5.4×1.21÷521),=2.1×1.1×0.54÷5.4÷1.21×521,=(2.1×521)×(1.1÷1.21)×(0.54÷5.4),=0.5×1011×0.1,=12×1011×110,=122.故答案為:122.