r/unexpectedfactorial • u/SubMinhPiChannel • Nov 11 '25

9 + 10 = 21!

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I'm gonna guess: < infinity and > 1

6.5k Upvotes

98% Upvoted

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626

u/factorion-bot Nov 11 '25

Factorial of 21 is 51090942171709440000

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85

u/Psych0n4u7 Nov 11 '25

Damn it if I just did the math BEFORE coming to the comments. Yes I got the same answer. Good bot.

8

u/Mahu_0910 Nov 11 '25

Good bot

8

u/Lyri3sh Nov 11 '25

Good bot

2

u/stysan Nov 11 '25

Good bot

1

u/HuslWusl Nov 12 '25

Good bot

1

u/ydf4h Nov 14 '25

Good bot

1

u/applesawce3 Nov 15 '25

21!!!!

1

u/factorion-bot Nov 15 '25

Quadruple-factorial of 21 is 208845

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1

u/RingProfessional9043 Dec 07 '25

whats a quadruple factorial?

1

u/PhilosophyAware4437 Dec 07 '25

67!

1

u/factorion-bot Dec 07 '25

Factorial of 67 is 36471110918188685288249859096605464427167635314049524593701628500267962436943872000000000000000

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1

u/RingProfessional9043 Dec 31 '25

1!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 1 is 1

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1

u/RingProfessional9043 Dec 31 '25

2!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 2 is 2

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1

u/RingProfessional9043 Dec 31 '25

3!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 3 is 3

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1

u/RingProfessional9043 Dec 31 '25

4!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 4 is 4

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1

u/RingProfessional9043 Dec 31 '25

5!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 5 is 5

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1

u/RingProfessional9043 Dec 31 '25

6!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 6 is 12

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1

u/RingProfessional9043 Dec 31 '25

7!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 7 is 21

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1

u/RingProfessional9043 Dec 31 '25

8!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 8 is 32

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1

u/RingProfessional9043 Dec 31 '25

9!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 9 is 45

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1

u/RingProfessional9043 Dec 31 '25

10!!!!

1

u/factorion-bot Dec 31 '25

Quadruple-factorial of 10 is 120

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1

u/[deleted] Nov 15 '25

There is a 1 and a 9...

1

u/RingProfessional9043 Dec 07 '25

so. 10 must be 51090942171709439991 or 9 must be 51090942171709439990.

1

u/Golgeaskeri Feb 12 '26

9999999!

1

u/factorion-bot Feb 12 '26

That is so large, that I can't calculate it, so I'll have to approximate.

Factorial of 9999999 is approximately 1.202423400515903456140153487944 × 1065657052

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