Methodology

Every computed value on this site — factors, primality, prime factorization, roman numerals, binary and hexadecimal representations, and the perfect/triangular/Fibonacci checks — is computed from one shared, tested math core rather than being typed in by hand or generated by three separately-maintained scripts that could quietly drift out of agreement. The /number/, /factors-of/, and /is-prime/ page families all call the exact same underlying functions for a given value, so they can never disagree with each other about the same number.

That math core ships with an automated test suite that checks it against known values before anything is published — for example, that 91 is correctly identified as composite (7 × 13), that 496 is confirmed as a perfect number, that 6,174 is verified to be Kaprekar’s constant behavior under the Kaprekar routine, and that round-tripping a Roman numeral through both conversion directions returns the original value. Trial division is used for factoring and primality checks, up to the square root of the target number in both cases, which is exact (not approximated) for every number in this site’s supported range.

Written guides and calculator explanations are researched and drafted per topic rather than assembled from a shared template — each one is checked for mathematical accuracy against the same standards as the computed pages. Where a number carries genuine historical, cultural, or mathematical significance beyond its bare computed facts (the curated notable numbers), that context is drawn from real, checkable sources rather than invented for padding.

If you find a computed value or a written explanation that looks wrong, the Contact page is the fastest way to report it — every report gets checked against the underlying math core directly.

One deliberate limitation, stated plainly rather than hidden: the site’s dedicated factor and prime-check pages cover numbers 1 through 550, and full computed number pages cover 1 through 1,000, because trial division up to the square root of a number stays fast and exact within that range but is not the efficient approach once numbers get genuinely large — which is a real computational fact, not an arbitrary cutoff chosen for convenience. Curated notable numbers beyond that range (into the millions) are covered individually where they carry documented significance, using the same tested functions, just applied one number at a time rather than generated as a full page range.