Easier than expected

Sum of the series of consecutive odd numbers starting from 1 is given by .. $\{ \dfrac {Last number+1} {2} \}^2$
Therefore the root is
$\\~\\ \dfrac{1789+1}{2}=895$
This is also the equal to the avrage * numbers in the arithmetic series.

Sum of 1st n odd numbers is n^2 .. Given sequence contains 895 numbers.. Hence square root of sum is 895