三百五十万 is a numeral expression meaning 'three million five hundred thousand' (3,500,000). In Chinese, large numbers group by ten-thousands (万), so 三百五十万 = 350 × 10,000. This row appears to have data issues: the pinyin field only gives 'sān bǎi' (covering only the first two characters) and the POS is marked as measure word (m), but 三百五十万 is a number, not a classifier. Use it as a standalone number before a measure word or noun.