# d21

The numbers with a 21 subscript use Base 21 Unovigesimal notation.

For more familiar numbers: See Thirteen in Base 10 Decimal

## Nearby Numbers

Positive, nonzero integers within three units

10
a21
Ten in Base 21 Unovigesimal
11
b21
Eleven in Base 21 Unovigesimal
12
c21
Twelve in Base 21 Unovigesimal
14
e21
Fourteen in Base 21 Unovigesimal
15
f21
Fifteen in Base 21 Unovigesimal
16
g21
Sixteen in Base 21 Unovigesimal

## Scientific Notation

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

## Reciprocal

A number multiplied with its reciprocal is one.

### `0.1cj81cj81cj8221`

The reciprocal of 13 in Base 21 Unovigesimal.

## Palindrome?

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

The number d21 is a palindrome.

## A Prime Number

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

Thirteen is the 6th prime number.   See primes in Base 21 Unovigesimal

## Not A Composite

Composites have more than just these two factors.

Thirteen is not a composite number because it has exactly two factors: One and Thirteen

## Prime Factors

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

The number thirteen has the following 1 prime factor:

13
d21
Thirteen in Base 21 Unovigesimal

## Prime Factorization

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

## Base Conversions

The number thirteen in 35 different bases