The Number

21991

Twenty-One Thousand Nine Hundred and Ninety-One

In Base 31 Untrigesimal Is

mrc31

The numbers with a 31 subscript use Base 31 Untrigesimal notation.

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

Nearby Numbers

Positive, nonzero integers within three units

21988
mr931
Twenty-One Thousand Nine Hundred and Eighty-Eight in Base 31 Untrigesimal
21989
mra31
Twenty-One Thousand Nine Hundred and Eighty-Nine in Base 31 Untrigesimal
21990
mrb31
Twenty-One Thousand Nine Hundred and Ninety in Base 31 Untrigesimal
21992
mrd31
Twenty-One Thousand Nine Hundred and Ninety-Two in Base 31 Untrigesimal
21993
mre31
Twenty-One Thousand Nine Hundred and Ninety-Three in Base 31 Untrigesimal
21994
mrf31
Twenty-One Thousand Nine Hundred and Ninety-Four in Base 31 Untrigesimal

Scientific Notation

Scientific notation expresses a quantity as the product of its significand with 10 raised to an integer exponent.

2.1991e4

Reciprocal

A number multiplied with its reciprocal is one.

0.001auqi5ebo64q31

The reciprocal of 21991 in Base 31 Untrigesimal.

Palindrome?

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

The number mrc31 is not a palindrome.

A Prime Number

A prime number is a positive integer that is divisible only by itself and one.

Twenty-one thousand nine hundred and ninety-one is the 2463rd prime number.   See primes in Base 31 Untrigesimal

Not A Composite

Composites have more than just these two factors.

Twenty-One Thousand Nine Hundred and Ninety-One is not a composite number because it has exactly two factors: One and Twenty-One Thousand 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 twenty-one thousand nine hundred and ninety-one has the following 1 prime factor:

21991
mrc31
Twenty-One Thousand Nine Hundred and Ninety-One in Base 31 Untrigesimal

Prime Factorization

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

mrc311 = mrc31

Base Conversions

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