Let the five consecutive integers be \( x - 2, x - 1, x, x + 1, x + 2 \), where \( x \) is the middle integer. The average (mean) of these integers is given by:
\[
\frac{(x - 2) + (x - 1) + x + (x + 1) + (x + 2)}{5} = 25.
\]
Simplify the numerator:
\[
\frac{(x - 2) + (x - 1) + x + (x + 1) + (x + 2)}{5} = \frac{5x}{5}.
\]
Thus, we have:
\[
\frac{5x}{5} = 25.
\]
Now, solve for \( x \):
\[
x = 25.
\]
Therefore, the five consecutive integers are \( 23, 24, 25, 26, 27 \), and the largest integer is \( \boxed{27} \).