In this page we are going to see the list of prime numbers up to 100 .

- Prime numbers are positive numbers greater than 1 .
- A number to be prime number it must be non-zero whole number.
- Prime numbers are the numbers that cannot be divided by any number except themselves and one.
- Prime numbers have only two factors.
- The two factors of prime numbers are one and the number itself.
- The way of finding the prime numbers is called integer factorization, or prime factorization.

The following are the

**prime numbers up to 100**2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.

## Greek Eratosthenes method to find prime numbers upto 100

1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |

11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |

21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |

31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 |

41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 |

51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 |

61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 |

71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 |

81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 |

91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 |

The Greek Eratosthenes formed a technique to find out these prime numbers, although it only worked over a restricted range:

- Write out the numbers from 1 to 100 in as shown above.
- Cross out the number 1, because all primes are greater than 1.
- Number 2 is a prime, so we can keep 2 as it is, and we cross out all the numbers that are multiplies of 2. (like 4,6,8,10 ….)
- Number 3 is also a prime number, so we keep 3 as it is and we cross out all the numbers that are the multiples of 3.( like 3,6,9,…….)
- The next number left is 5 , so we keep 5 as it is and we cross out all the numbers that are the multiples of 5 ( like 10 ,15, 20, 25…..)
- At last the number left in the first row is number 7, now we keep 7 as it is and we cross out all the numbers that are the multiples of 7 ( like 14, 21, 28 ……)
- Now all of the remaining numbers in the table are prime numbers.

## Some facts about prime numbers

- The only even prime number is 2 and remaining even numbers can be divided by 2 so it cant be prime number.
- No prime number greater than 5 ends in a 5.Since any number greater than 5 that ends in a 5 can be divided by 5 so it cant be prime number.
- Zero and 1 are not considered prime numbers.
- Except for 0 and 1, a number is called as either a prime number or a composite number.