# Minimal parasitic number

One of the things I like so much about math is that you always get to know a new concept. Recently, I learned about parasitic numbers. I was asked what is the minimal parasitic 4-number. So, I wrote down the following simple code, and found out:

```
def new_num(n):
n_str = str(n)
res = n_str[-1:] + n_str[:-1]
return int(res)
```

```
def is_num(n, k):
new_n = new_num(n)
if new_n == k * n:
return True
else:
return False
```

```
for i in range(1000000):
if is_num(i,4):
print(i)
```

```
0
102564
128205
153846
179487
205128
230769
```