whatpower.py

import sys
import fractions
import operator
import collections

def factorize( n ):
    assert type(n) in (int, long)
    assert n > 0
    div = 2
    while n > 1:
        if 0 == n % div:
            n /= div
            yield div
        else:
            div += 1

def whatpower(n):
    if 1 == n: return (1,1)
    fc = collections.Counter( factorize( n ) )
    p = reduce( fractions.gcd, fc.values() )
    b = reduce( operator.mul, map( lambda x:(x[0]**(x[1]/p)), fc.items()) )
    return (b,p)

if __name__ == '__main__':
	if len( sys.argv ) <= 1:
		print "What number?"
		sys.exit()
	try:
		print "%d^%d" % whatpower( long( sys.argv[1] ) )
	except:
		print "Wrong value: %s" % sys.argv[1]