Prime Factorization Calculator
Prime factorization is the process of decomposing a composite number into a product of prime numbers. According to the Fundamental Theorem of Arithmetic, every integer greater than 1 can be represented uniquely as a product of prime numbers.
Step-by-Step Calculation:
How to Find Prime Factorization
To find the prime factorization of a number:
- Step 1: Start with the smallest prime number (2).
- Step 2: If divisible, divide and repeat.
- Step 3: If not, try the next prime (3, 5, 7, 11...).
- Step 4: Continue until the quotient is 1.
Common Prime Factorizations
Here is a table of common numbers and their prime factorizations:
| Number | Prime Factorization | Is Prime? |
|---|---|---|
| 1 | 1 | Yes |
| 2 | 2 | Yes |
| 3 | 3 | Yes |
| 4 | 2 × 2 | No |
| 5 | 5 | Yes |
| 6 | 2 × 3 | No |
| 7 | 7 | Yes |
| 8 | 2 × 2 × 2 | No |
| 9 | 3 × 3 | No |
| 10 | 2 × 5 | No |
| 11 | 11 | Yes |
| 12 | 2 × 2 × 3 | No |
| 13 | 13 | Yes |
| 14 | 2 × 7 | No |
| 15 | 3 × 5 | No |
| 16 | 2 × 2 × 2 × 2 | No |
| 18 | 2 × 3 × 3 | No |
| 19 | 19 | Yes |
| 20 | 2 × 2 × 5 | No |
| 21 | 3 × 7 | No |
| 22 | 2 × 11 | No |
| 23 | 23 | Yes |
| 24 | 2 × 2 × 2 × 3 | No |
| 25 | 5 × 5 | No |
| 26 | 2 × 13 | No |
| 27 | 3 × 3 × 3 | No |
| 28 | 2 × 2 × 7 | No |
| 29 | 29 | Yes |
| 30 | 2 × 3 × 5 | No |
| 31 | 31 | Yes |
| 32 | 2 × 2 × 2 × 2 × 2 | No |
| 33 | 3 × 11 | No |
| 34 | 2 × 17 | No |
| 35 | 5 × 7 | No |
| 36 | 2 × 2 × 3 × 3 | No |
| 37 | 37 | Yes |
| 38 | 2 × 19 | No |
| 39 | 3 × 13 | No |
| 40 | 2 × 2 × 2 × 5 | No |
| 41 | 41 | Yes |
| 42 | 2 × 3 × 7 | No |
| 44 | 2 × 2 × 11 | No |
| 45 | 3 × 3 × 5 | No |
| 46 | 2 × 23 | No |
| 47 | 47 | Yes |
| 48 | 2 × 2 × 2 × 2 × 3 | No |
| 49 | 7 × 7 | No |
| 50 | 2 × 5 × 5 | No |
| 51 | 3 × 17 | No |
| 52 | 2 × 2 × 13 | No |
| 53 | 53 | Yes |
| 54 | 2 × 3 × 3 × 3 | No |
| 55 | 5 × 11 | No |
| 56 | 2 × 2 × 2 × 7 | No |
| 57 | 3 × 19 | No |
| 58 | 2 × 29 | No |
| 59 | 59 | Yes |
| 60 | 2 × 2 × 3 × 5 | No |
| 61 | 61 | Yes |
| 62 | 2 × 31 | No |
| 63 | 3 × 3 × 7 | No |
| 64 | 2 × 2 × 2 × 2 × 2 × 2 | No |
| 65 | 5 × 13 | No |
| 66 | 2 × 3 × 11 | No |
| 67 | 67 | Yes |
| 68 | 2 × 2 × 17 | No |
| 69 | 3 × 23 | No |
| 70 | 2 × 5 × 7 | No |
| 71 | 71 | Yes |
| 72 | 2 × 2 × 2 × 3 × 3 | No |
| 73 | 73 | Yes |
| 74 | 2 × 37 | No |
| 75 | 3 × 5 × 5 | No |
| 76 | 2 × 2 × 19 | No |
| 77 | 7 × 11 | No |
| 78 | 2 × 3 × 13 | No |
| 79 | 79 | Yes |
| 80 | 2 × 2 × 2 × 2 × 5 | No |
| 81 | 3 × 3 × 3 × 3 | No |
| 83 | 83 | Yes |
| 84 | 2 × 2 × 3 × 7 | No |
| 85 | 5 × 17 | No |
| 86 | 2 × 43 | No |
| 87 | 3 × 29 | No |
| 88 | 2 × 2 × 2 × 11 | No |
| 90 | 2 × 3 × 3 × 5 | No |
| 91 | 7 × 13 | No |
| 92 | 2 × 2 × 23 | No |
| 93 | 3 × 31 | No |
| 94 | 2 × 47 | No |
| 95 | 5 × 19 | No |
| 96 | 2 × 2 × 2 × 2 × 2 × 3 | No |
| 97 | 97 | Yes |
| 98 | 2 × 7 × 7 | No |
| 99 | 3 × 3 × 11 | No |
| 100 | 2 × 2 × 5 × 5 | No |
| 101 | 101 | Yes |
| 102 | 2 × 3 × 17 | No |
| 104 | 2 × 2 × 2 × 13 | No |
| 105 | 3 × 5 × 7 | No |
| 108 | 2 × 2 × 3 × 3 × 3 | No |
| 110 | 2 × 5 × 11 | No |
| 111 | 3 × 37 | No |
| 112 | 2 × 2 × 2 × 2 × 7 | No |
| 114 | 2 × 3 × 19 | No |
| 115 | 5 × 23 | No |
| 119 | 7 × 17 | No |
| 120 | 2 × 2 × 2 × 3 × 5 | No |
| 121 | 11 × 11 | No |
| 123 | 3 × 41 | No |
| 124 | 2 × 2 × 31 | No |
| 125 | 5 × 5 × 5 | No |
| 126 | 2 × 3 × 3 × 7 | No |
| 128 | 2 × 2 × 2 × 2 × 2 × 2 × 2 | No |
| 130 | 2 × 5 × 13 | No |
| 132 | 2 × 2 × 3 × 11 | No |
| 133 | 7 × 19 | No |
| 135 | 3 × 3 × 3 × 5 | No |
| 136 | 2 × 2 × 2 × 17 | No |
| 138 | 2 × 3 × 23 | No |
| 140 | 2 × 2 × 5 × 7 | No |
| 143 | 11 × 13 | No |
| 144 | 2 × 2 × 2 × 2 × 3 × 3 | No |
| 147 | 3 × 7 × 7 | No |
| 150 | 2 × 3 × 5 × 5 | No |
| 152 | 2 × 2 × 2 × 19 | No |
| 153 | 3 × 3 × 17 | No |
| 154 | 2 × 7 × 11 | No |
| 160 | 2 × 2 × 2 × 2 × 2 × 5 | No |
| 162 | 2 × 3 × 3 × 3 × 3 | No |
| 165 | 3 × 5 × 11 | No |
| 168 | 2 × 2 × 2 × 3 × 7 | No |
| 169 | 13 × 13 | No |
| 171 | 3 × 3 × 19 | No |
| 175 | 5 × 5 × 7 | No |
| 176 | 2 × 2 × 2 × 2 × 11 | No |
| 180 | 2 × 2 × 3 × 3 × 5 | No |
| 182 | 2 × 7 × 13 | No |
| 184 | 2 × 2 × 2 × 23 | No |
| 186 | 2 × 3 × 31 | No |
| 187 | 11 × 17 | No |
| 189 | 3 × 3 × 3 × 7 | No |
| 192 | 2 × 2 × 2 × 2 × 2 × 2 × 3 | No |
| 195 | 3 × 5 × 13 | No |
| 196 | 2 × 2 × 7 × 7 | No |
| 198 | 2 × 3 × 3 × 11 | No |
| 200 | 2 × 2 × 2 × 5 × 5 | No |
| 204 | 2 × 2 × 3 × 17 | No |
| 205 | 5 × 41 | No |
| 207 | 3 × 3 × 23 | No |
| 210 | 2 × 3 × 5 × 7 | No |
| 212 | 2 × 2 × 53 | No |
| 216 | 2 × 2 × 2 × 3 × 3 × 3 | No |
| 220 | 2 × 2 × 5 × 11 | No |
| 221 | 13 × 17 | No |
| 224 | 2 × 2 × 2 × 2 × 2 × 7 | No |
| 225 | 3 × 3 × 5 × 5 | No |
| 230 | 2 × 5 × 23 | No |
| 232 | 2 × 2 × 2 × 29 | No |
| 240 | 2 × 2 × 2 × 2 × 3 × 5 | No |
| 242 | 2 × 11 × 11 | No |
| 243 | 3 × 3 × 3 × 3 × 3 | No |
| 245 | 5 × 7 × 7 | No |
| 248 | 2 × 2 × 2 × 31 | No |
| 250 | 2 × 5 × 5 × 5 | No |
| 252 | 2 × 2 × 3 × 3 × 7 | No |
| 255 | 3 × 5 × 17 | No |
| 256 | 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 | No |
| 260 | 2 × 2 × 5 × 13 | No |
| 264 | 2 × 2 × 2 × 3 × 11 | No |
| 270 | 2 × 3 × 3 × 3 × 5 | No |
| 273 | 3 × 7 × 13 | No |
| 275 | 5 × 5 × 11 | No |
| 280 | 2 × 2 × 2 × 5 × 7 | No |
| 285 | 3 × 5 × 19 | No |
| 286 | 2 × 11 × 13 | No |
| 288 | 2 × 2 × 2 × 2 × 2 × 3 × 3 | No |
| 293 | 293 | Yes |
| 294 | 2 × 3 × 7 × 7 | No |
| 297 | 3 × 3 × 3 × 11 | No |
| 300 | 2 × 2 × 3 × 5 × 5 | No |
| 308 | 2 × 2 × 7 × 11 | No |
| 310 | 2 × 5 × 31 | No |
| 312 | 2 × 2 × 2 × 3 × 13 | No |
| 315 | 3 × 3 × 5 × 7 | No |
| 320 | 2 × 2 × 2 × 2 × 2 × 2 × 5 | No |
| 324 | 2 × 2 × 3 × 3 × 3 × 3 | No |
| 325 | 5 × 5 × 13 | No |
| 330 | 2 × 3 × 5 × 11 | No |
| 336 | 2 × 2 × 2 × 2 × 3 × 7 | No |
| 350 | 2 × 5 × 5 × 7 | No |
| 351 | 3 × 3 × 3 × 13 | No |
| 360 | 2 × 2 × 2 × 3 × 3 × 5 | No |
| 364 | 2 × 2 × 7 × 13 | No |
| 375 | 3 × 5 × 5 × 5 | No |
| 378 | 2 × 3 × 3 × 3 × 7 | No |
| 385 | 5 × 7 × 11 | No |
| 392 | 2 × 2 × 2 × 7 × 7 | No |
| 396 | 2 × 2 × 3 × 3 × 11 | No |
| 400 | 2 × 2 × 2 × 2 × 5 × 5 | No |
| 420 | 2 × 2 × 3 × 5 × 7 | No |
| 425 | 5 × 5 × 17 | No |
| 432 | 2 × 2 × 2 × 2 × 3 × 3 × 3 | No |
| 440 | 2 × 2 × 2 × 5 × 11 | No |
| 441 | 3 × 3 × 7 × 7 | No |
| 450 | 2 × 3 × 3 × 5 × 5 | No |
| 462 | 2 × 3 × 7 × 11 | No |
| 468 | 2 × 2 × 3 × 3 × 13 | No |
| 480 | 2 × 2 × 2 × 2 × 2 × 3 × 5 | No |
| 495 | 3 × 3 × 5 × 11 | No |
| 500 | 2 × 2 × 5 × 5 × 5 | No |
| 504 | 2 × 2 × 2 × 3 × 3 × 7 | No |
| 510 | 2 × 3 × 5 × 17 | No |
| 525 | 3 × 5 × 5 × 7 | No |
| 528 | 2 × 2 × 2 × 2 × 3 × 11 | No |
| 539 | 7 × 7 × 11 | No |
| 540 | 2 × 2 × 3 × 3 × 3 × 5 | No |
| 560 | 2 × 2 × 2 × 2 × 5 × 7 | No |
| 572 | 2 × 2 × 11 × 13 | No |
| 585 | 3 × 3 × 5 × 13 | No |
| 588 | 2 × 2 × 3 × 7 × 7 | No |
| 600 | 2 × 2 × 2 × 3 × 5 × 5 | No |
| 612 | 2 × 2 × 3 × 3 × 17 | No |
| 625 | 5 × 5 × 5 × 5 | No |
| 630 | 2 × 3 × 3 × 5 × 7 | No |
| 675 | 3 × 3 × 3 × 5 × 5 | No |
| 676 | 2 × 2 × 13 × 13 | No |
| 684 | 2 × 2 × 3 × 3 × 19 | No |
| 700 | 2 × 2 × 5 × 5 × 7 | No |
| 720 | 2 × 2 × 2 × 2 × 3 × 3 × 5 | No |
| 760 | 2 × 2 × 2 × 5 × 19 | No |
| 770 | 2 × 5 × 7 × 11 | No |
| 792 | 2 × 2 × 2 × 3 × 3 × 11 | No |
| 828 | 2 × 2 × 3 × 3 × 23 | No |
| 875 | 5 × 5 × 5 × 7 | No |
| 880 | 2 × 2 × 2 × 2 × 5 × 11 | No |
| 891 | 3 × 3 × 3 × 3 × 11 | No |
| 900 | 2 × 2 × 3 × 3 × 5 × 5 | No |
| 980 | 2 × 2 × 5 × 7 × 7 | No |
| 1001 | 7 × 11 × 13 | No |
| 1155 | 3 × 5 × 7 × 11 | No |
| 1260 | 2 × 2 × 3 × 3 × 5 × 7 | No |
| 1287 | 3 × 3 × 11 × 13 | No |
| 1575 | 3 × 3 × 5 × 5 × 7 | No |
| 1700 | 2 × 2 × 5 × 5 × 17 | No |
| 2016 | 2 × 2 × 2 × 2 × 2 × 3 × 3 × 7 | No |
| 2017 | 2017 | Yes |
| 2018 | 2 × 1009 | No |
| 2019 | 3 × 673 | No |
| 2020 | 2 × 2 × 5 × 101 | No |
| 2021 | 43 × 47 | No |
| 2022 | 2 × 3 × 337 | No |
| 2023 | 7 × 17 × 17 | No |
| 2024 | 2 × 2 × 2 × 11 × 23 | No |
| 2205 | 3 × 3 × 5 × 7 × 7 | No |
| 2800 | 2 × 2 × 2 × 2 × 5 × 5 × 7 | No |
| 10000 | 2 × 2 × 2 × 2 × 5 × 5 × 5 × 5 | No |
The Factor Tree Method
A factor tree is a diagram that helps visualize the process of prime factorization. Write the number at the top, then draw two branches to any pair of factors. Continue branching each composite number until every endpoint is a prime. For example, for 60: split into 6 and 10, then 6 into 2 and 3, and 10 into 2 and 5. The primes are 2, 2, 3, and 5, so 60 = 2 squared x 3 x 5.
Step-by-Step Guide to Using This Calculator
Enter any positive integer greater than 1 in the Number field and click Calculate. The calculator will display whether the number is prime or composite, list all prime factors, show the total number of divisors, and provide a complete factor list. Use the Clear button to enter a new number. The step-by-step panel walks through the division method used to find the result.
Fundamental Theorem of Arithmetic
This theorem guarantees that every integer greater than 1 can be expressed as a product of prime numbers in exactly one way, apart from the order of the factors. This uniqueness is what makes prime factorization so powerful and reliable. Whether you use a factor tree, trial division, or any other valid method, you will always arrive at the same set of prime factors for any given number.
Applications in Mathematics and Beyond
Prime factorization is essential for finding the Greatest Common Factor and Least Common Multiple of numbers, which are needed for fraction arithmetic. In cryptography, the security of RSA encryption depends on the computational difficulty of factoring large semiprimes. Hash functions and random number generators also rely on properties of prime numbers. Understanding prime factorization builds strong foundations for algebra, number theory, and computer science.
Tips and Common Mistakes
Always start with the smallest prime (2) when using trial division. Do not include 1 in your factorization since it is not prime. Check your work by multiplying the prime factors back together. Remember that if no prime up to the square root of n divides n, then n itself is prime. Practice with small numbers first to build intuition before tackling larger values.
Conclusion
Prime factorization is a cornerstone of number theory with applications in cryptography, computer science, and everyday mathematics. Understanding how to decompose numbers into their prime factors is essential for many mathematical operations and real-world problem solving.