# Python Program to Check Armstrong Number Using Functions

Let’s have a glance at how to check Armstrong’s number using the function in Python programming language.

## What is Armstrong’s number?

Armstrong number is a number that is equivalent to the sum of cubes of its digits. For example 0, 1, 153, 370, 371 and 407 are the Armstrong numbers. Let’s try to understand why 407 is an Armstrong number.
`(4*4*4)+(0*0*0)+(7*7*7)=407`

## Python Program to Check Armstrong Number Using Functions

```def check_power(a, x):
if x==0:
return 1
if x%2==0:
return check_power(a, x/2)*check_power(a, x/2)
return a*check_power(a, x/2)*check_power(a, x/2)

def check_order(x):

n = 0
while (x!=0):
n = n+1
x = x/10
return n

# Function to check whether the given number is Armstrong number or not
def isArmstrong (x):
n = 0
while (x!=0):
n = n+1
x = x/10
n = check_order(x)
temp = x
sum1 = 0
while (temp!=0):
r = temp%10
sum1 = sum1 + check_power(r, n)
temp = temp/10

return (sum1 == x)

x = 407
if isArmstrong(x)==1:
print x, 'is an armstrong number'```

Output:

`407 is an armstrong number`