Owlet puzzle #9
Released Tuesday, July 14, 2026 UTC
2520
the answer for puzzle #9
The five clues
- A four-digit multiple of 720.
- It is divisible by every integer from 1 to 10.
- In fact, it is the smallest such number.
- LCM(1,2,...,10).
- Also equals half of seven factorial.
Backstory
2520 = LCM(1..10) = 7! / 2 is the smallest number divisible by every integer from 1 to 10, and the 18th highly composite number with 48 divisors. It appears in Egyptian and Sumerian metrology, and equals 5·7·8·9 as well as 2³·3²·5·7.
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