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A239661
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Divisors of 1089.
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0
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OFFSET
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1,2
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COMMENTS
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Divisors of 33^2.
The sum of divisors of 1089 is equal to 1729, the Hardy-Ramanujan number: A000203(1089) = A001235(1) = 1729.
The aliquot divisors of 1089 are also the powers of 3 written in base 26, see A004668.
Also 1089 is widely used in magic tricks because it can be produced from any two three-digit numbers (see Links section).
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LINKS
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EXAMPLE
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Sigma(1089) = 1 + 3 + 9 + 11 + 33 + 99 + 121 + 363 + 1089 = 1729.
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MATHEMATICA
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy,fini,full
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AUTHOR
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STATUS
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approved
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