# Get all digits in a number

### Get all digits in a number with minimum space.

Given a positive integer `num`, the following function iterates its digits from the most insignificant digit to the most significant one:

``````def get_digits_right_to_left(num: int):
while num > 0:
yield num % 10
num //= 10
``````

Here’s another way to write it using Python’s `divmod` function:

``````def get_digits_right_to_left(num: int):
while num > 0:
num, digit = divmod(num, 10)
yield digit
``````

Can we iterate the digits from the most significant digit to the most insignificant one?

``````def get_digits(num: int):
div = 1
while num // div:
div *= 10
div //= 10
while div:
yield num // div
num %= div
div //= 10
``````

Another version using `divmod`:

``````def get_digits(num: int):
div = 1
while num // div:
div *= 10
div //= 10
while div:
digit, num = divmod(num, div)
div //= 10
yield digit
``````

### Find the number of digits that evenly divide a positive number

Among all the digits of a positive integer `num`, write a function to determine how many of them evenly divide `num`. For example, 13204 has 3 digits that evenly divide 13204: 1, 2, and 4 since `13204 % 1 = 13204 % 2 = 0 = 13204 % 4 = 0`.

Note that digit 0 does not divide any positive integer.

``````def count_digits_evenly_divide(num: int) -> int:
return sum(d != 0 and num % d == 0 for d in get_digits(num))
``````

### Self-dividing number

A self-dividing number is a number that is divisible by every digit it contains. For example, 128 is a self-dividing number as `128 % 1 = 128 % 2 = 128 % 8 = 0`.

A self-dividing number is not allowed to contain the digit zero.

The function below checks if a number is self-dividing:

``````def is_self_dividing(num: int) -> bool:
return all(d != 0 and num % d == 0 for d in get_digits(num))
``````