# Is 391 a Prime Number?

Is 391 a prime number? Numbers having only 2 factors, i.e. 1 and the number itself are known as prime numbers whereas numbers with more than 2 factors are known as composite. The answer to the question whether 391 is a prime or composite is - * "391 is a composite number."* Now, let us find out how and why is 391 a prime number or a composite number?

**Is 391 a prime number? -**No**Is 391 a composite number? -**Yes**Is 391 a perfect square? -**No**Prime Factors of 391 -**17, 23**Factors of 391 -**1, 17, 23, 391

## Is 391 a Prime Number?

No, 391 is not a prime number. The number 391 is divisible by 1, 17, 23, 391. For a number to be classified as a prime number, it should have exactly two factors. Since 391 has more than two factors, i.e. 1, 17, 23, 391, it is not a prime number.

## Why is 391 not a Prime Number?

To understand whether 391 is prime or composite, it is important to find its factors.

**Factors of 391:** 1, 17, 23, 391

Since 391 has more than 2 factors, we can say that 391 is not a prime number.

## Is 391 a Composite Number?

Yes, since 391 has more than two factors i.e. 1, 17, 23, 391. In other words, 391 is a composite number because 391 has more than 2 factors.

**Problem Statements: **

Is 391 a Prime Number? | No |

Is 391 a Composite Number? | Yes |

Multiples of 391 | 391, 782, 1173, 1564, 1955, 2346, 2737, 3128, 3519, 3910 |

Cube Root of 391 | 7.312368 |

Is 391 an Odd Number? | Yes |

Is 391 an Even Number? | No |

Is 391 a Perfect Square? | No |

Is 391 a Perfect Cube? | No |

Square of 391 | 152881 |

Square Root of 391 | 19.77372 |

**Fun Facts: **

- Prime numbers greater than 5 can be represented in the form of either 6n + 1 or 6n - 1. Example - 71 is a prime number and it can be written as 71 = 6 × 12 - 1
- All primes except 2 are odd.
- 23 is the smallest prime number having consecutive digits.

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