991
Prime Number 991: Properties and Meaning
Short answer
The number 991 is an odd prime, so its only positive divisors are 1 and 991.
Is 991 prime?
ClassificationPrimeParityOddDivisor count2AbundanceDeficient
What is the prime factorization of 991?
Prime factorization
991
What are the divisors of 991?
Divisor count
2
Divisor sum
992
Proper divisor sum
1
How is 991 classified?
How is 991 represented in other numeral systems?
Decimal
991
Binary
1111011111
Octal
1737
Hexadecimal
3DF
Roman
CMXCILearn more →
In words
nine hundred ninety one
Roots and powers
Square root
31.480152 Approximate
Cube root
9.969910 Approximate
Nearest lower square
961
Nearest higher square
1024
Nearest lower cube
729
Nearest higher cube
1000
What are the digit properties of 991?
Which numbers are related to 991?
Compare this number
FAQ for 991
- Is 991 prime?
- Yes
- What is the prime factorization of 991?
- 991
- Is 991 a perfect square?
- No
- What is 991 in binary?
- 1111011111
- What is 991 in Roman numerals?
- CMXCI