MathDB

4

Part of 1991 IberoAmerican

Problems(1)

Five-digit number

Source: Ibero-American Olympiad 1991, Problem 4

5/3/2007
Find a positive integer nn with five non-zero different digits, which satisfies to be equal to the sum of all the three-digit numbers that can be formed using the digits of nn.
number theory proposednumber theory