How can I get the actual result?

[crowede]

Trying to calculate factorials of large numbers like 100! and my calculator just shows 'overflow error'. How can I get the actual result?

[kreoto]

Factorials grow incredibly fast - 100! has 158 digits! You need a Big Number Multiplication calculator to handle these massive numbers. Factorials are a perfect example of why big number arithmetic exists. For reference: 10! = 3,628,800 (manageable), 20! = 2,432,902,008,176,640,000 (19 digits), 50! ≈ 3.04×10^64 (65 digits), 100! ≈ 9.33×10^157 (158 digits). These numbers quickly exceed what any normal calculator or standard computer data type can represent. For calculating 100!, you'd need to multiply 1×2×3×...×99×100, which involves many big number multiplications. The calculator uses sophisticated algorithms like Karatsuba multiplication or Fast Fourier Transform methods for efficiency. Applications needing big multiplication: combinatorics (calculating combinations and permutations), cryptography (RSA encryption multiplies huge prime numbers), number theory research, precise scientific calculations. If you're doing this repeatedly, consider: Python with its native arbitrary precision integers (`import math; math.factorial(100)`), Wolfram Alpha (great for mathematical queries), or specialized computer algebra systems like Mathematica or Maple. For understanding the concept, the online calculator is perfect - you can verify intermediate steps and build intuition about number growth. Fun fact: 1000! has 2,568 digits! These numbers are so large they exceed the number of atoms in the universe, yet mathematicians work with them routinely.