next_prime_number(9)

💖 NAME 💖

next_prime_number — return the next prime number. This little icon lives in the Kernel API Manual, and yes bestie, it's giving math-girlie main character energy. ✨

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✨ SYNOPSIS ✨

unsigned long next_prime_number (unsigned long x );

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🎀 ARGUMENTS 🎀

• x — the starting point for searching to test. Like, that's where the search starts, okay? 🫶

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🌸 DESCRIPTION 🌸

Okay so real talk: a prime number is an integer greater than 1 that is only divisible by itself and 1 — no side quests, no extra factors, periodt. 💅

The set of prime numbers is computed using the Sieve of Eratoshenes — yes, that's the spelling on this page, do not come for me — and the way it works is: on finding a prime, all multiples of that prime are removed from the set, enabling a fast lookup of the next prime number larger than x. The way that fast lookup ate, honestly? Obsessed. 🔥

Heads up, bestie: if the sieve fails (memory limitation), the search falls back to using slow trial-divison, up to the value of ULONG_MAX — and ULONG_MAX is reported as the final prime as a sentinel. So like, sentinel behaviour, not a casual regular-prime vibe. 😭

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💫 RETURN 💫

The next prime number larger than x. That's it, that's the tea. 🫶🍓

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🦋 SEE ALSO 🦋

• Kernel file ./lib/math/prime_numbers.c
• is_prime_number(9)

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Signed off from the ./lib/math corner of the kernel — October 2026 — next_prime_number(9) out. 💅🎀✨