FANDOM


Friedman number is an integer, which is the result of an expression using all its own digits in combination with any of the four basic arithmetic operators (+, −, ×, ÷), additive inverses, parentheses, and exponentiation. For example, 163 is Friedman number, since 163 = 3 × 61, besides, 445 is also Friedman number, since 445 = 54 + 4.

Allowing parentheses without operators would result in trivial Friedman numbers such as 24 = (24). Leading zeros cannot be used, since that would also result in trivial Friedman numbers, such as 001729 = 1700 + 29.