```
1) Convert to base n and check the pattern "10*" appears in that base representation
eg 4 base 4 = 10
16 base 4 = 100
3 base 3 = 10
9 base 3 = 100
Integer.toString(num,n).matches("10*")
2) (Math.log10(num)/Math.log10(n))%1==0
eg Math.log10(64)/Math.log10(4) = 3.0
3.0 % 1 = 0
```