836

Number
$836$ (eight hundred and thirty-six) is:


 * $2^2 \times 11 \times 19$


 * The $1$st positive integer whose square is a palindromic number with an even number of digits:
 * $836^2 = 698 \, 896$ ($6$ digits)


 * The $2$nd weird number after $70$:
 * $\map \sigma {836} - 836 = 844$: its aliquot parts are $1$, $2$, $4$, $11$, $19$, $22$, $38$, $44$, $76$, $209$, $418$, from which $836$ cannot be made.


 * The $4$th non-palindromic square root after $26$, $264$, $307$ of a palindromic square:
 * $836^2 = 698 \, 896$


 * The $13$th primitive abundant number after $20$, $70$, $88$, $104$, $272$, $304$, $368$, $464$, $550$, $572$, $650$, $748$:
 * $1 + 2 + 4 + 11 + 19 + 22 + 38 + 44 + 76 + 209 + 418 = 844 > 836$

Also see

 * Tau Function of 836