16777216 = 224, a perfect 24th power.
16777216 = 88. 11, 88, and 99 are the only powers that have the same number of decimal digits as the power.
16777216 (88) is the number of labeled mappings from n points to themselves, for n = 8.
16777216 is the smallest number beginning with 1 and having exactly n prime divisors (counted with multiplicity), for n = 24.
Computer bug report: Fatal error: Allowed memory size of 16777216 bytes exhausted.
In the RGB color model, the Truecolor scheme defines 256 shades of red, blue, and green, which results in 16,777,216 color variations for each pixel (256 x 256 x 256).