The Number

991

Nine Hundred and Ninety-One

In Base 11 Undecimal Is

82111

The numbers with a 11 subscript use Base 11 Undecimal notation.

For more familiar numbers: See Nine Hundred and Ninety-One in Base 10 Decimal

Nearby Numbers

Positive, nonzero integers within three units

988
81911
Nine Hundred and Eighty-Eight in Base 11 Undecimal
989
81a11
Nine Hundred and Eighty-Nine in Base 11 Undecimal
990
82011
Nine Hundred and Ninety in Base 11 Undecimal
992
82211
Nine Hundred and Ninety-Two in Base 11 Undecimal
993
82311
Nine Hundred and Ninety-Three in Base 11 Undecimal
994
82411
Nine Hundred and Ninety-Four in Base 11 Undecimal

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.

0.001385716a4855894a11

The reciprocal of 991 in Base 11 Undecimal.

Palindrome?

A numerical palindrome has the same value when all of its digits are reversed.

The number 82111 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 11 Undecimal

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 prime factors of a positive integer are the integers that divide it exactly and are also prime.

The number nine hundred and ninety-one has the following 1 prime factor:

991
82111
Nine Hundred and Ninety-One in Base 11 Undecimal

Prime Factorization

The prime factorization of a positive integer is the unique list of prime factors together with their multiplicities

821111 = 82111

Base Conversions

The number nine hundred and ninety-one in 35 different bases