When 636 is subtracted from a number, it reduces to its two–fifth. Which of the following would be twice that number?

Let's denote the unknown number as $x$.

According to the problem, when 636 is subtracted from $x$, the result is two-fifths of $x$. This can be written as:

$x - 636 = \frac{2}{5}x$

To solve for $x$, we first isolate $x$ on one side of the equation. Start by eliminating the fraction by multiplying both sides by 5:

$5(x - 636) = 2x$

This simplifies to:

$5x - 3180 = 2x$

Next, we move all terms involving $x$ to one side of the equation:

$5x - 2x = 3180$

This simplifies to:

$3x = 3180$

Now, solve for $x$ by dividing both sides by 3:

$x = \frac{3180}{3}$

$x = 1060$

The problem asks for twice that number, so we calculate:

$2 \times 1060 = 2120$

Therefore, the answer is:

$2120$