64

Number
$64$ (sixty-four) is:


 * $2^6$


 * The $8$th square number after $1, 4, 9, 16, 25, 36, 49$:
 * $64 = 8 \times 8$


 * The $7$th almost perfect number after $1, 2, 4, 8, 16, 32$:
 * $\sigma \left({64}\right) = 127 = 2 \times 64 - 1$