Calculatrice de Propriétés Numériques.

What is the prime factorization of a number?

Prime factorization breaks a number down into the prime numbers that multiply together to make it. For example 12 = 2 x 2 x 3, written as 2^2 x 3. Every whole number above 1 has exactly one prime factorization, which is why it is the fingerprint used to find GCF, LCM and to simplify fractions.

What makes a number perfect, abundant or deficient?

Add up all the divisors of a number except the number itself. If the total equals the number it is perfect (6 = 1+2+3, and 28 = 1+2+4+7+14). If the total is bigger it is abundant (12 gives 1+2+3+4+6 = 16). If the total is smaller it is deficient (8 gives 1+2+4 = 7). Perfect numbers are rare: only 6, 28, 496 and 8128 are below 10,000.

Why is 1 not a prime number?

A prime number has exactly two distinct divisors: 1 and itself. The number 1 only has one divisor, so it fits neither the definition of prime nor of composite. Excluding it also keeps prime factorization unique — otherwise you could tack on any number of 1s.

Why does this calculator show no divisors for 0?

Every non-zero integer divides 0 evenly, because 0 divided by anything is 0. That makes the list of divisors infinite rather than a finite set, so the calculator shows a note instead of a misleading list. Zero also has no Roman numeral, since Roman numerals start at I.

Can negative numbers have factors and Roman numerals?

Factors are listed for the size of the number (the magnitude), so -12 shows 1, 2, 3, 4, 6, 12. Roman numerals do not exist for zero or negative values, so a dash is shown. Binary, hexadecimal and octal are shown with a leading minus sign. Perfect, abundant and deficient are only defined for positive numbers.

How big a number can I enter?

Up to 1,000,000,000,000 (one trillion) in either direction. The factor search uses trial division up to the square root, so even a large prime returns instantly without freezing your browser.