You misread the time there; those are not microseconds.
From the documentation:
Time: The total amount of time spent executing the line in the timer's units. In the header information before the tables, you will see a line "Timer unit:" giving the conversion factor to seconds. It may be different on different systems.
Emphasis mine. Your output shows each Timer unit is about 0.428 microseconds. The totals match if you multiply the units with the Timer unit value:
>>> unit = 4.27654e-07
>>> 2426873 * unit + 1491105 * unit
1.675538963612