The Number

81991

Eighty-One Thousand Nine Hundred and Ninety-One

In Base 15 Quindecimal Is

1946115

The numbers with a 15 subscript use Base 15 Quindecimal notation.

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

Nearby Numbers

Positive, nonzero integers within three units

81988
1945d15
Eighty-One Thousand Nine Hundred and Eighty-Eight in Base 15 Quindecimal
81989
1945e15
Eighty-One Thousand Nine Hundred and Eighty-Nine in Base 15 Quindecimal
81990
1946015
Eighty-One Thousand Nine Hundred and Ninety in Base 15 Quindecimal
81992
1946215
Eighty-One Thousand Nine Hundred and Ninety-Two in Base 15 Quindecimal
81993
1946315
Eighty-One Thousand Nine Hundred and Ninety-Three in Base 15 Quindecimal
81994
1946415
Eighty-One Thousand Nine Hundred and Ninety-Four in Base 15 Quindecimal

Scientific Notation

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

8.1991e4

Reciprocal

A number multiplied with its reciprocal is one.

0.000093dd2db661d79815

The reciprocal of 81991 in Base 15 Quindecimal.

Palindrome?

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

The number 1946115 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 thousand nine hundred and ninety-one is a composite number with 16 total factors (including 1 and itself).   See primes in Base 15 Quindecimal

A Composite

Composites have more than just these two factors.

Eighty-one thousand nine hundred and ninety-one is a composite number with 16 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 thousand nine hundred and ninety-one has the following 4 prime factors:

7
715
Seven in Base 15 Quindecimal
13
d15
Thirteen in Base 15 Quindecimal
17
1215
Seventeen in Base 15 Quindecimal
53
3815
Fifty-Three in Base 15 Quindecimal

Prime Factorization

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

7151 · d151 · 12151 · 38151 = 1946115

Base Conversions

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