Okay as any maths geek, or doctor who fan, knows a happy prime is both a prime number and a happy number. A prime number is any number that can only be divided by itself or 1 to give an integer (whole number). A happy number is an integer number where each of the numbers that make it up is squared then added together, then each number that makes the new total is squared and added together. This repeats until you either get 1 or it continues on an indeffinate loop. A number which give 1 is said to be a happy number. For example 7;

7^2 = 4^9

4^2 + 9^2 = 97

9^2 + 7^2 = 130

1^2 + 3^2 + 0^2 = 10

1^2 + 0^2 = 1

So seven is both happy and a prime.

My challenge is thus, who can come up with the highest happy prime that has the lowest number of 'steps'

for example 2309 has 5 steps

2309 = 94

94 = 97

97 = 130

130 = 10

10 = 1

You should show the steps.