What sum of fact...?

Number Theory Level 5

If $a$ is natural number such that it equals the sum of the factorials of its decimal digits. Find sum of all such $a$ in base 10.

The answer is 40733.

1 solution

Adwait Sharma
Jan 31, 2015

include<stdio.h>

include<conio.h>

int main()

{

int n=1,x,y=0,p,m,z;

while(n<10000000) /*  7*9!<9999999  */
{

x=n;

p=0;

z=0;

while(x>0)

{

    p=x%10;

    m=1;

    while(p>0)

    {

        m=m*p;

        p--;

    }

    z=z+m;

    x=x/10;

}

if(z==n)

{

    y=y+n;

}

n++;

}

printf("The Answer is %d",y);

getch();

}