El número atrasado no es una edición limitada.

Not exactly. In this kind of context, número often means an issue of a magazine, comic, newspaper, or similar publication.

So el número atrasado is not just the delayed number in a mathematical sense. It means something like a back issue or previous issue.

El is the definite article, so it means the. Spanish uses it when talking about a specific thing that is already known from the context.

So:

• el número = the issue
• un número = an issue

If the speaker is referring to one particular back issue, el número makes sense.

Here atrasado means something like back, previous, or older and not current, especially in publishing.

In other contexts, atrasado can also mean:

• late
• delayed
• behind

But with número, it usually refers to a past issue rather than a current one.

In Spanish, adjectives usually come after the noun.

So:

• número atrasado
• edición limitada

This is the most normal word order. Putting atrasado before the noun would sound unusual here and could change the tone or emphasis.

Usually, no—not in this expression.

For a back issue, número atrasado is the established phrase.
Retrasado can mean delayed, but it is not the normal choice here.

Also, retrasado can have other meanings in different contexts, some of them sensitive or offensive, so it is better for learners not to swap it in casually.

In Spanish, no normally goes directly before the conjugated verb.

So:

• no es = is not
• no tengo = I do not have
• no sabemos = we do not know

That is the standard way to make a sentence negative.

Because this sentence is identifying or classifying something, not describing a temporary state.

Spanish usually uses ser for:

• identity
• classification
• definitions
• what something is

So:

• No es una edición limitada = It is not a limited edition

If you used estar, it would sound wrong here, because limited edition is being treated as a category, not a temporary condition.

Because edición is a feminine singular noun.

That means the article and adjective must match it:

• una = feminine singular article
• limitada = feminine singular adjective

Compare:

• un libro limitado = a limited book
• una edición limitada = a limited edition

This is basic gender and number agreement in Spanish.

Yes. Spanish normally puts the noun first and the adjective after it.

So English:

• limited edition

becomes Spanish:

• edición limitada

This is a very common and natural phrase.

The accent marks show where the stress goes:

• número → stress on the first syllable: NÚ-me-ro
• edición → stress on the last syllable: e-di-CIÓN

These marks are not optional. They are part of the correct spelling.

For English speakers, they are especially useful because they help with pronunciation and also distinguish the standard written form.

Most likely, yes.

Because of número atrasado, the sentence sounds like it is about an issue of a magazine, comic, or similar publication. Then edición limitada is saying that this back issue is not a special limited edition.

So even though edición limitada can be used for products, the word número strongly points toward publishing here.