Square Miles to Square Micrometers: the quick answer
1 mi² = 2.58999 × 10¹⁸ µm²
1 square mile equals 2.58999 × 10¹⁸ square micrometers
To convert square miles to square micrometers, multiply the value by 2.58999 × 10¹⁸. To go the other way, multiply square micrometers by 3.86102 × 10⁻¹⁹ to get square miles.