For the 13th root of a 100-digit number there are 7,992,563 possibilities, in the range 41,246,264 - 49,238,826.

This is the last official world record for extracting the 13th root of a 100-digit number.

If you want to find the square root of a number that isn't an integer, say 54782.917.

He extracted the 77th root of a 148-digit number in 18 seconds, while it took about 10 minutes to program the related operation for computer.

The digital root of a triangular number is 1, 3, 6 or 9.

On 27 August 1976, he calculated the 73rd root of a 500-digit number in 2 minutes and 43 seconds.

On 6 April 2005, he calculated the 13th root of a 200-digit number in 8 minutes 33 seconds.

One night he calculated in his head the square root of a number with 53 digits.

Is this not the root of a great number of current social and cultural problems?

For the square roots of a negative or complex number, see below.