This number is a prime.
The smallest of three "Beagle Boys" primes. The Beagle Boys menaced Scrooge McDuck in Disney comics and TV shows. Each had a six digit number emblazoned on their shirts for identification (like a prison number). The numbers were made up of 2 three-digit numbers each using permutations of '1', '6', and '7'. The other Beagle Boys primes are 716671 and 761671. [Breshears]