The Number
991
Nine Hundred and Ninety-One
In Base 18 Octodecimal Is
31118
The numbers with a 18 subscript use Base 18 Octodecimal notation.
For more familiar numbers: See Nine Hundred and Ninety-One in Base 10 Decimal
Nearby Numbers
Positive, nonzero integers within three units
Scientific Notation
Scientific notation expresses a quantity as the product of its significand with 10 raised to an integer exponent.
9.91e2
Reciprocal
A number multiplied with its reciprocal is one.
0.005fgd20h005fgd18
The reciprocal of 991 in Base 18 Octodecimal.
Palindrome?
A numerical palindrome has the same value when all of its digits are reversed.
The number 31118 is not a palindrome.
A Prime Number
A prime number is a positive integer that is divisible only by itself and one.
Nine hundred and ninety-one is the 167th prime number. See primes in Base 18 Octodecimal
Not A Composite
Composites have more than just these two factors.
Nine Hundred and Ninety-One is not a composite number because it has exactly two factors: One and Nine Hundred and Ninety-One
Prime Factors
The number nine hundred and ninety-one has the following 1 prime factor:
Prime Factorization
The prime factorization of a positive integer is the unique list of prime factors together with their multiplicities
311181
= 31118
Base Conversions
The number nine hundred and ninety-one in 35 different bases