# Is 991 a Prime Number?

Is 991 a prime number? Yes. If a number has only two factors, i.e., 1 and the number itself, it is known as a prime number. In contrast, composite numbers have more than two factors. By this explanation, can we answer the question - is 991 a prime number? According to the definition mentioned above, we can say, * "yes, 991 is a prime number."* Now let us take a look at the detailed solution of why is 991 a prime number?

**Is 991 a prime number? -**Yes**Is 991 a composite number? -**No**Factors of 991 -**1, 991**Prime Factors of 991 -**991**Is 991 a perfect square? -**No

## Is 991 a Prime Number?

Yes, 991 is a prime number. The number 991 is divisible only by 1 and the number itself. For a number to be classified as a prime number, it should have exactly two factors, 1 and the number itself. Since 991 has exactly two factors, i.e., 1 and 991, it is a prime number.

## How is 991 a Prime Number?

To understand whether 991 is composite or prime, it is important to find its factors.

**Factors of 991:** 1, 991

Therefore, we can say that 991 is a prime number since it has only 2 factors.

## Is 991 a Composite Number?

No, since 991 has only two factors, i.e., 1 and 991. In other words, 991 is not a composite number because 991 doesn’t have more than 2 factors.

**Problem Statements: **

Is 991 a Prime Number? | Yes |

Is 991 a Composite Number? | No |

Cube Root of 991 | 9.969887 |

Is 991 an Odd Number? | Yes |

Is 991 a Perfect Cube? | No |

Square Root of 991 | 31.480152 |

Multiples of 991 | 991, 1982, 2973, 3964, 4955, 5946, 6937, 7928, 8919, 9910 |

Is 991 an Even Number? | No |

Is 991 a Perfect Square? | No |

**Fun Facts: **

- A semiprime number is a composite number that is the product of exactly two prime numbers. Example - 697 is semiprime, since 697 can be written as 17 × 41.
- Numbers X and Y are said to be coprime if they have only one common factor that is 1.
- A palindrome prime is a prime number that when read in reverse order results in the same number. Examples - 787, 373, 353

**☛ Also Check: **

- Is 553 a Prime Number? - No
- Is 85 a Prime Number? - No
- Is 187 a Prime Number? - No
- Is 225 a Prime Number? - No
- Is 297 a Prime Number? - No
- Is 673 a Prime Number? - Yes
- Is 1331 a Prime Number? - No
- Is 617 a Prime Number? - Yes

visual curriculum