You know that prime number, natural number, Armstrong number but do you know about Friedman number. Well if you don’t know about this magical  number then this article for you. Friedman numbers are named after Erich Friedman, a now-retired mathematics professor at Stetson University, located in DeLand, Florida.

# What is Friedman number?

According to Wikipedia, A Friedman number is an integer, which represented in a given numeral system, is the result of a non-trivial expression using all its own digits in combination with any of the four basic arithmetic operators (+, −, ×, ÷), additive inverses, parentheses, exponentiation, and concatenation.

In a simple explanation, it is number which can be achieve by applying arithmetic operators with using their own digits with any combination.

## Example:

The expressions of the first few Friedman numbers are:

 number expression number expression number expression number expression 25 52 127 27−1 289 (8+9)2 688 8×86 121 112 128 28−1 343 (3+4)3 736 36+7 125 51+2 153 3×51 347 73+4 1022 210−2 126 6×21 216 62+1 625 56−2 1024 (4−2)10

Before moving further with this number, do you also know about the Why 6174 is a magical number? You can check from below link:

Well now we can see some more pictorial example of Friedman number. What is Friedman number? How to find it [Source Code]Now most probably, you understand the concept of this number. Now lets move to the source code of find a number is Friedman number or not. Program is written in Java.