Frequently Asked Questions

Your name is normalized (consistent casing, accents folded, trimmed spaces), then run through a Huffman code that packs the letters into a compact bit pattern. We add a length tag, encrypt the result with a small Feistel cipher keyed by your personal 3-character decryption key, and search for a value that's prime — adjusting an internal counter until one falls out.

The result is deterministic and reversible: with your prime and your key, the math runs backwards to recover the original name.

Curious about the details? Our Prime Wisdom articles walk through every step, and the Decoder lets you run the reverse operation yourself.

Names are more common than you'd think — but primes are rarer than you'd hope. Here's the good news: our algorithm accounts for this.

If your exact normalized name has already been claimed, our system gives you a different decryption key, which sends the math down a different branch and lands on a different prime. Two people named Alicia Prime get two different primes, two different keys, and two different certificates — both legitimate, both unique.

And because the number line is infinite, we will never, ever run out of primes. Euclid proved that around 300 BCE, and we're still grateful.

Absolutely. Every prime in our registry belongs to exactly one owner. No sharing, no duplicates, no "it's complicated." Your prime is yours and yours alone — recorded permanently in our public registry.

You can verify this anytime by checking the registry.

Yes! We encourage it. Head over to our Prime Test page and paste your number in. We use the Miller-Rabin primality test with 16 rounds — the same standard used in cryptography.

Or if you're feeling old-school, try dividing it by every integer up to its square root. We'll wait.

Your prime fits into one of three sizes — 64, 96, or 128 bits — chosen automatically based on how much of your name needs to be packed in. That works out to roughly 20, 30, or 39 digits. Short names land in the smaller buckets; longer names step up.

Even at the smallest size, the number space is enormous — there are more 64-bit primes than there are seconds since the Big Bang. Your number is unique to you, and unique-enough to the observable universe.

A Prime for You is a novelty and entertainment product. You receive a personalized prime, a certificate, and registry options to enjoy — but primes themselves belong to mathematics, not to any one person as private property.

We don't grant exclusive legal title to a number on the number line. What you're buying is the experience, the certificate, and your place in our registry (if you want it). For the full picture, see our Terms of Service.

A Prime for You is a digital product. After purchase, you receive a beautifully designed PDF certificate that you can download, print at home, or send to a professional printer for framing.

We've found this gives you the most flexibility — print it on archival paper, poster-size it for a wall, or keep it as a digital keepsake. Your prime, your call.

That's actually how many of our primes find their owners! Just enter the recipient's name and your email at checkout. You'll receive the certificate and owner link, which you can forward or print and wrap up with a bow.

Mathematically unique, personally meaningful, and impossible to re-gift. The perfect present.

After payment, our system immediately generates your prime number, creates your certificate, and registers your entry in the public registry. You'll receive an email with:

• A link to your prime's dedicated page
• Your downloadable PDF certificate
• A shareable link to show off your number

The whole process takes just a few seconds — though we show you a fun animation while the math happens behind the scenes.

We offer a full money-back guarantee for 30 days from the date of purchase. If you're not delighted, you can request a refund from the Order Management section on your personal prime page (the link from your purchase email), or reach out via our support page.

Details match our Terms of Service — we're straightforward about what you get and how to change your mind.

Yes. After purchase, you can correct or update the display name on your certificate up to three times from your personal prime page (the secure link we email you).

If you've used all three and still need a change, contact support and we'll help.

All payments go through Stripe, an industry-standard processor. The exact cards and local payment methods available depend on what Stripe offers for your country — you'll see your options on the checkout screen before you pay.

We never see or store your full card number or CVC; Stripe handles that under strict PCI rules. Stripe also emails you a receipt after purchase.

Your purchase email has the magic link to your prime page and certificate — treat it like a ticket. If it's gone, we're still here: open our support page and tell us roughly when you ordered and which email you used at checkout (and the name on the order if you remember it). We'll verify you and get you back in.

Yes — customers in many countries can check out. Stripe decides which payment methods and currencies are available for your location; whatever you see at checkout is what we can accept right now.

If checkout won't complete for your region, let us know and we'll see what we can do.

Any sales tax, VAT, or similar charges depend on your location and how our Stripe account is configured. When applicable, Stripe calculates and shows those amounts before you pay — you'll always see the final total on the checkout screen.

We're happy to refine this answer as our Stripe tax settings evolve; the checkout page is always the source of truth for what you'll be charged.

You sure can! Our Bulk Orders page lets you generate primes for an entire group — perfect for corporate gifts, wedding favors, classroom projects, or any occasion where "a number that will outlast the sun" feels appropriate.

Each person gets their own unique prime and certificate.

$11 per prime. Why $11? Because it's prime, naturally. We also offer volume discounts on bulk orders.

That's entirely up to you. When you order, you choose one of three privacy levels:

• Public — your name and prime appear in the registry for all to admire
• Anonymous — your prime is listed, but your name is hidden
• Unlisted — nothing appears publicly at all

You can change your privacy setting at any time through our support page.

The minimum needed to run the service: your name (to generate the prime), your email (to deliver the certificate), and your privacy preference. We don't sell data, don't run ads, and don't track you across the web.

Full details in our Privacy Policy — which, unlike most privacy policies, you might actually enjoy reading.

Your connection to our site uses HTTPS. Payments run entirely through Stripe; we never see or store your full card details (see our Privacy Policy).

We keep only the data needed to generate your prime, deliver your certificate, and honor your registry privacy choice. Your prime is generated using a small reversible cipher keyed by your personal decryption key — the math runs backwards only with that key, which is shown to you on your certificate, never published, and never sent over the network. We explain the security tradeoffs in the FAQ just below.

Infrastructure runs on Cloudflare with access limited to what's required to operate the service. You control whether your name appears in the public registry.

It depends on whether they have your decryption key.

Your prime is generated by a reversible cipher: with the prime and the 3-character decryption key from your certificate, anyone can run the math backwards on our Decoder page and recover the normalized name. That's a feature — it lets you (and anyone you choose to share with) verify that the prime really encodes the name on the certificate.

Without the key, recovery is harder but not impossible: the key is intentionally short (a puzzle mechanic, not a secrecy boundary), and a determined attacker could try keys until one produces a name-shaped result. We rate-limit the decode endpoint to slow this down, but A Prime for You is a novelty product, not a cryptographic vault. If a name is genuinely sensitive, choose Anonymous or Unlisted at checkout — those modes don't disclose the key publicly.

(Older primes purchased under earlier algorithm versions — a1.x and a2.x — are one-way and have no decryption key. Nothing about those primes changes.)

A prime number is a number greater than 1 that can only be divided evenly by 1 and itself. So 7 is prime (nothing divides it evenly except 1 and 7), but 6 is not (2 × 3 = 6).

Primes are the atoms of arithmetic — every whole number is either prime or can be built by multiplying primes together. They're the building blocks of all of mathematics, and they've fascinated humans for over two thousand years.

Never. Euclid proved around 300 BCE that there are infinitely many primes. His proof is elegant: assume you have a complete list, multiply them all together, add 1, and you've found a number that none of your "complete" list can divide. Contradiction. More primes must exist.

We wrote about this in more detail in our article on Euclid's proof. It's one of the most beautiful arguments in all of mathematics.

We use the Miller-Rabin primality test with 16 rounds of verification. This is a probabilistic test, but with 16 rounds, the chance of a composite number sneaking through is less than 1 in 2³² — or about 1 in 4 billion.

For context, you're more likely to be struck by lightning while winning the lottery while finding a four-leaf clover. Your prime is prime.

Our algorithm picks the smallest cipher block that fits your name plus a few bits of structure. Short names get 64-bit blocks (~20-digit primes); mid-length names get 96 (~30 digits); longer names get 128 (~39 digits). Picking the smallest viable block keeps the prime printable and typeable on a certificate, while still being far larger than anyone could brute-force search by hand.

Even the smallest option is a huge number space. The largest is in the same ballpark as the symmetric keys used in serious cryptography — comfortably more values than there are atoms in a sand grain.

Your decryption key is a small 3-character code (letters and digits, like A2X or K7P) shown on your certificate. It's the personal twist that turns your name into your specific prime — and the secret that lets the math run backwards. Two people with the same normalized name get different keys, which is how they end up with different primes.

Run yours through the Decoder to see your name come back out, character by character.

Your key appears on your certificate (PDF) and on your prime's owner page (the magic link in your purchase email). If you've still got either of those, your key is one click or one zoom away.

If both are gone, contact support — we'll verify you and help you recover access. (One small note: the key is yours to keep but isn't critical to owning your prime; see the next question.)

Absolutely. Your prime is yours regardless of the key — the key is for the reversibility experience (the Decoder page) and for proving that the prime really encodes your name. You don't need it to view your prime, share it, print the certificate, or claim your spot in the registry.

Think of the key as a fun puzzle attached to your prime, not the lock that keeps you out of it.