Surprisingly there are only three numbers that can be written as the sum of fourth powers of their digits:

1634 = 14 + 64 + 34 + 44
8208 = 84 + 24 + 04 + 84
9474 = 94 + 44 + 74 + 44

As 1 = 14 is not a sum it is not included.

The sum of these numbers is 1634 + 8208 + 9474 = 19316.

Find the sum of all the numbers that can be written as the sum of fifth powers of their digits


In [1]:
pow5 = dict(((str(i), i ** 5) for i in range(10)))
pow5


Out[1]:
{'0': 0,
 '1': 1,
 '2': 32,
 '3': 243,
 '4': 1024,
 '5': 3125,
 '6': 7776,
 '7': 16807,
 '8': 32768,
 '9': 59049}

In [2]:
def foo():
    j = []
    for i in range(2, 1000000):
        if i == sum((pow5[c] for c in str(i))):
            j.append(i)
    return sum(j)

In [3]:
%timeit foo()
foo()


1 loops, best of 3: 2.46 s per loop
Out[3]:
443839