pre_text: A summary of options outstanding and vested as of December 31, 2019 is as follows: The total intrinsic value of options exercised during 2019, 2018, and 2017 was $318.5 million, $17.4 million, and $6.6 million, respectively. The weighted average grant date fair value of options granted during the years ended December 31, 2019, 2018, and 2017, was $19.80, $9.07, and $6.44 per share, respectively. During the year ended December 31, 2019, 2,141,078 options vested. There were 2,939,947 options unvested as of December 31, 2019. As of December 31, 2019, $30.3 million of total unrecognized compensation cost related to stock options was expected to be recognized over a weighted average period of approximately 2.5 years.
table: Options Outstanding Options Vested and Exercisable
table: Exercise Prices Number Outstanding Weighted Average Life (in Years) Number Vested and Exercisable Weighted Average Life (in Years)
table: $1.50 to $1.90 32,913 1.4 32,913 1.4
table: 2.86 to 6.40 209,126 3.3 209,126 3.3
table: 8.04 to 11.72 498,869 4.2 498,869 4.2
table: 12.20 to 15.06 2,227,421 6.7 1,587,924 6.5
table: 16.06 to 24.00 1,772,062 8.1 560,632 8.1
table: 31.99 to 42.21 847,010 9.0 42,839 8.7
table: 55.10 to 79.25 297,341 9.5 12,492 9.3
table: 5,884,742 2,944,795
question: Analyse this data from a financial earnings document. What is the number of outstanding options whose exercise price are between $1.50 to $6.40?