Sum of Divisors Calculator
Sum of Divisors Calculator
Adding up every divisor of a number — known in number theory as the sigma function — is the calculation behind identifying perfect, abundant, and deficient numbers, three classic categories from classical number theory. Enter any whole number here and this calculator lists and sums its divisors, both including and excluding the number itself. Prime numbers always have the simplest possible divisor sum, since their only divisors are 1 and themselves.
- This calculates the "sigma function" (σ) from number theory, which sums every positive divisor of a number, including 1 and the number itself.
- Subtracting the number itself gives the sum of proper divisors, which is the value used to test for perfect, abundant, and deficient numbers.
- Prime numbers always have a divisor sum equal to n + 1, since their only divisors are 1 and themselves.
How do I calculate the sum of divisors of a number?
List every number that divides evenly into it (including 1 and the number itself), then add them all together.
What is the sum of divisors of 28?
The divisors of 28 are 1, 2, 4, 7, 14, and 28, which add up to 56.
Sum of Divisors Calculator
Adding up every divisor of a number — known in number theory as the sigma function — is the calculation behind identifying perfect, abundant, and deficient numbers, three classic categories from classical number theory. Enter any whole number here and this calculator lists and sums its divisors, both including and excluding the number itself. Prime numbers always have the simplest possible divisor sum, since their only divisors are 1 and themselves.
- This calculates the "sigma function" (σ) from number theory, which sums every positive divisor of a number, including 1 and the number itself.
- Subtracting the number itself gives the sum of proper divisors, which is the value used to test for perfect, abundant, and deficient numbers.
- Prime numbers always have a divisor sum equal to n + 1, since their only divisors are 1 and themselves.
How do I calculate the sum of divisors of a number?
List every number that divides evenly into it (including 1 and the number itself), then add them all together.
What is the sum of divisors of 28?
The divisors of 28 are 1, 2, 4, 7, 14, and 28, which add up to 56.