Number Tools

Compare two values, apply percentage increases or decreases with compounding, and reverse-calculate wholes from known parts—all in a single, shareable summary.

Generate secure random integers in bulk with unique and sorting options, clipboard-ready results, descriptive stats, and a history of your recent runs.

Test integers up to 10¹⁸ with deterministic Miller–Rabin, inspect nearest primes, optional factorisation, and divisor statistics for deeper number theory insights.

Calculate n!, permutations, and combinations with exact BigInt precision, digit counts, trailing zeros, and scientific notation.

Convert numbers to Roman numerals and Roman numerals back to numbers with validation, breakdowns, and copy-ready results.

Convert integers between bases 2–36, keep prefixes, group digits for readability, and copy quick references for binary, octal, decimal, and hexadecimal all at once.

Paste or type a dataset to instantly see mean, median, quartiles, deviation, geometric and harmonic means, potential outliers, and a copy-ready summary.

Paste lists of integers to get the gcd, lcm, prime factors, divisor counts, and step-by-step Euclidean reductions—ideal for classrooms and number theory work.

Round numbers by decimal places or significant figures with half-up, banker’s, floor, ceil, truncation, and step rounding—complete with comparison tables.

Switch between decimals, simplified fractions, mixed numbers, and percentages with smart denominator control, approximation error, and copy-ready results.