I have posted this question in StackExchange, but it didn't get any answers there. This question is important for my research. I got stuck on an infinite product which even WolframAlpha can answer. Here's it: $$\prod_{n=2}^{\infty}\left(1-\frac{1}{n!}\right)$$ - This is surely convergent, many tests work. Wolfram Alpha couldn't evaluate it, but gave an approximate value $$0.395338567367445566032356200431180613$$ - The decimal expansion is [OEIS A282529](https://oeis.org/A282529), but the entry doesn't have much information. This constant is conjectured to be irrational, transcendental, and normal. - [This Math.SE question](https://math.stackexchange.com/questions/2009336/closed-form-for-prod-i-2-infty-1-frac1i) asks specifically for a closed form, but it has no answers, so it doesn't solve my question. Here's the work I did: \begin{align} \prod_{n=2}^{\infty}\left(1-\frac{1}{n!}\right)&=\lim_{N\to\infty}\frac{\prod_{N\geq n\geq2}(n!-1)}{\prod_{N\geq n\geq2}n!}\\[6pt] &=\lim_{N\to\infty}\frac{\prod_{N\geq n\geq2}(n!-1)}{1\cdot1\cdot2\cdot1\cdot2\cdot3\cdots1\cdot2\cdot\cdots N}\\[6pt] &=\lim_{N\to\infty}\frac{\prod_{N\geq n\geq2}(n!-1)}{1^N2^{N-1}3^{N-2}\cdots(N-1)^2N^1} \end{align} Now I don't know how to proceed. L'Hopital's rule doesn't work, since the numerator isn't a function (it is, but the product should be solved before differentiating). > How can I evaluate it? A link to an article containing information about the constant will also help. Any help would be appreciated. Note: A closed form isn't necessary; converting the product into a sum or integral will also help. Some special function representations will also be good.