Find the greatest number which will divide $45,72$ and $999$ leaving remainder as $5,2$ and $9$.

Simplify the following:

$96-[18-\{63÷7-(18-5 of 3)\left\}\right]$

Simplify the following:

$81 of [60-\{8\times 7-(13-5 of 2)\left\}\right]$

Simplify the following:

$49-[23+\{27-(9 of 3÷27)\left\}\right]$

Simplify the following:

$72+[65-\{7\times 56÷8-(7 of 3-21)\left\}\right]$

Write all the factors of the given number

$37$

Write all the factors of the following:

$56$