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factorion




A natural number that equals of the sums of the factorials of its digits in a given base. The only known decimal factorions are 1 = 1!, 2 = 2!, 145 = 1! + 4! + 5!, and 40585 = 4! + 0! + 5! + 8! + 5!.


Related category

   • TYPES OF NUMBERS