1980

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Number

$1980$ (one thousand, nine hundred and eighty) is:

$2^2 \times 3^2 \times 5 \times 11$


The smallest term of the amicable triplet $\tuple {1980, 2016, 2556}$:
$\map \sigma {1980} = \map \sigma {2016} = \map \sigma {2556} = 6552 = 1980 + 2016 + 2556$


The $2$nd integer after $954$ whose digits are unchanged when subtracting its reversal:
$1980 - 0891 = 1089$


Also see


Sources