The Number

81

Eighty-One

In Base 11 Undecimal Is

7411

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

For more familiar numbers: See Eighty-One in Base 10 Decimal

Nearby Numbers

Positive, nonzero integers within three units

78
7111
Seventy-Eight in Base 11 Undecimal
79
7211
Seventy-Nine in Base 11 Undecimal
80
7311
Eighty in Base 11 Undecimal
82
7511
Eighty-Two in Base 11 Undecimal
83
7611
Eighty-Three in Base 11 Undecimal
84
7711
Eighty-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.

8.1e1

Reciprocal

A number multiplied with its reciprocal is one.

0.01548313a3592642311

The reciprocal of 81 in Base 11 Undecimal.

Palindrome?

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

The number 7411 is not a palindrome.

Not A Prime Number

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

Eighty-one is a composite number with 5 total factors (including 1 and itself).   See primes in Base 11 Undecimal

A Composite

Composites have more than just these two factors.

Eighty-one is a composite number with 5 total factors (including 1 and itself).

Prime Factors

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

The number eighty-one has the following 1 prime factor:

3
311
Three in Base 11 Undecimal

Prime Factorization

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

3114 = 7411

Base Conversions

The number eighty-one in 35 different bases