The Biology Department is considering purchasing new microscopes from Schultz Optics. The diameter of the field of view using the high power (40x) objective is 0.35 millimeters (mm). If you were to use this microscope, and under high power found that the longest dimension of a particular cell fills 1/6 of the diameter of the field, what is the size of the cell in reality? Provide your answer in micrometers (um), rounded to the nearest whole number. Do not include units in your answer.