2941526 mi^2
The first thing you should know to solve this problem is the following conversion:
1mi = 1609.34m
Applying the conversion we have:
2941526 * (1609.34 / 1) ^ 2 = 7.61848E + 12 m ^ 2
Answer:
The land area of Australia in square meters is:
7.61848E + 12 m ^ 2