Calculation methodology

We accept integers from 0 through 1,000,000,000. The input field recognizes Western, Arabic-Indic (١٢٣), and Persian (۱۲۳) digits, and ignores grouping separators such as commas and spaces. Decimal points, plus/minus signs, and scientific notation are not accepted.

A prime number is greater than 1 and divisible only by 1 and itself. By the standard mathematical definition, 0 and 1 are neither prime nor composite. Prime factorization is shown as a product of prime powers, such as 2² × 3.

Divisors are the positive integers that divide a number with no remainder. A perfect number equals the sum of its proper divisors (excluding itself); an abundant number's proper divisors sum to more than the number; a deficient number's sum to less.

Binary, octal, and hexadecimal forms are derived directly from the number's decimal value. Roman numerals follow the classical convention and are shown only for numbers from 1 through 3999; outside that range, no standard Roman numeral is displayed.

Arabic number words follow natural reading conventions. English number words omit the word "and" inside hundreds (for example, three hundred sixty rather than three hundred and sixty) — a fixed convention applied consistently across the site.