Prime Factorization – TI-84 Evo Math Program

Prime Factorization program on a TI-84 Evo

The TI-84 Evo has no built-in way to break a number into its prime factors, so this program does it for you.

Send it to your calculator

Plug the calculator into your computer with a USB cable, then use the button below. If something is not working, see troubleshooting.

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Open it on the calculator

  1. Press the prgm key. The PROGRAMMING menu opens.
    The prgm key highlighted on the TI-84 Evo keyboard
    TI-84 Evo PROGRAMMING menu with 1: TI-Basic highlighted
  2. Press enter to select TI-Basic. The list of TI-Basic programs opens.
    TI-84 Evo TI-Basic program list showing 1: PFACTOR
  3. Press enter on PFACTOR in the program list, which puts prgmPFACTOR on the home screen.
  4. Press enter to run it. The program asks for a number.
    Prime Factorization program on the TI-84 Evo asking for a number

Factor a number

  1. Type the number you want to factor and press enter. Enter 360 and it answers 2^3·3^2·5.
    Prime Factorization program on the TI-84 Evo factoring 360 into 2 cubed times 3 squared times 5

The dots between the numbers mean multiply and the carets mean powers, so that line reads 2 to the third, times 3 squared, times 5. Repeated primes are grouped that way to keep a long factorization on one line: 8 comes back as 2^3.

When the number is already prime

If the number has no smaller factors to pull out, the program says so instead of handing the number back to you. Type 97 and it answers 97 is prime.

Prime Factorization program on the TI-84 Evo answering 97 is prime

Good to know

  • Run it again with one keypress. Pressing enter on the home screen repeats whatever you ran last, so right after a run, a single enter brings the number prompt straight back.
  • Prime factors are the start of simplifying a radical. Splitting the number under a square root into primes is how you simplify it by hand. If that is what you came for, the Radical Simplifier program goes straight there, turning √50 into 5√2.
  • Greatest common factor and least common multiple are already built in. Press math, arrow right to the NUM tab, and you will find gcd( and lcm(, which take two numbers and answer directly. Typing gcd(360,84 gives 12, no factoring needed.
  • It works on whole numbers of 2 or more. A decimal, or anything below 2, gets a plain one-line note rather than an error screen. Type 2.5 and it answers "Whole numbers 2 or more".
    Prime Factorization program on the TI-84 Evo answering Whole numbers 2 or more when the input is 2.5

More TI-84 Evo Math Programs

← All TI-84 Evo math programs