Twenty-Eight Function Calculator for Long Numbers. A page that adds, subtracts, multiplies, divides, calculates factorials, combinations and permutations, finds primes less than 10,000,000,000 and takes logarithms, exponentials, powers, roots, trigonometric and hyperbolic functions of rather arbitrarily large numbers. Twenty-Eight Function Calculator for Big Numbers. A page that adds, subtracts, multiplies, divides, calculates factorials, combinations and permutations, finds primes less than 10,000,000,000 and takes logarithms, exponentials, powers, roots, trigonometric and hyperbolic functions of rather arbitrarily large numbers.