### Prime Numbers 1 to 20

There are 8 prime numbers, 7 odd Prime Numbers 1 to 20

#### How to Find Prime numbers 1 to 20?

**Step-1** Remove all numbers divisible by 2 from the table list.

First, make a table of all numbers from 1 to 20. Remove the numbers that are divisible by 2 from the table list.

**Step-2** In the second step, remove the numbers that are divisible from 3 from the list.

**Step-3** The number left after dividing by 3 will be prime numbers.

#### Sum of prime number between 1 to 20

There are 8 numbers from 1 to 20 and their sum is 77. Sum 2+3+5+7+11+13+17+19 = 77

#### Sum of all odd prime numbers between 1 to 20

There are 7 numbers from 1 to 20 and their sum is 75. Sum 3+5+7+11+13+17+19 = 75

#### A co-prime number between 1 to 20

1,2 | 2,3 | 3,5 | 13,17 | 1,3 |

2,5 | 13,19 | 3,7 | 1,4 | 2,7 |

3,11 | 1,5 | 2,9 | 3,13 | 1,6 |

2,11 | 3,17 | 1,7 | 2,13 | 3,19 |

1,8 | 2,15 | 1,9 | 2,17 | 1,10 |

2,19 | 1,11 | 2,21 | 2,23 | 1,12 |

### How many prime numbers are there between 0 and 20?

There are 8 prime numbers and 7 odd prime numbers from 1 to 20.

### Is 1 a prime number?

1 is not a prime number but a natural number.

### Why 1 is not a prime number?

Prime numbers by definition have only two factors. There is only one factor of 1 so it is not a prime number but a natural number.

### What is the greatest prime number between 1 to 20?

The greatest prime number between 1 to 20 is 19 which is also an odd prime number.

### What are the smallest prime numbers between 1 and 20?

The smallest prime number between 1 and 20 is 2 not 1. 2 is the only-one even prime number

### Which is the even prime number 1 to 20?

There are 2 even prime numbers between 1 to 20 numbers.

### Is 2 a prime number?

Yes! 2 is even prime number.

### Is 3 a prime number?

Yes! 3 is odd prime.

### Is 4 a prime number?

No! natural number

### Is 5 a prime number?

Yes! 5 is odd prime number

### Is 6 a prime number?

No! 6 is natural number

### Is 7 a prime number?

Yes! 7 is odd prime number

### Is 8 a prime number?

No! 8 is natural and even number

### Is 9 a prime number?

No! 9 natural number and odd number

### Is 10 a prime number?

No! 10 natural and even number