The Number

21561

Twenty-One Thousand Five Hundred and Sixty-One

Nearby Numbers

Positive, nonzero integers within three units

21558
Twenty-One Thousand Five Hundred and Fifty-Eight
21559
Twenty-One Thousand Five Hundred and Fifty-Nine
21560
Twenty-One Thousand Five Hundred and Sixty
21562
Twenty-One Thousand Five Hundred and Sixty-Two
21563
Twenty-One Thousand Five Hundred and Sixty-Three
21564
Twenty-One Thousand Five Hundred and Sixty-Four

Scientific Notation

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

2.1561e4

Reciprocal

A number multiplied with its reciprocal is one.

0.00004638003803163119

The reciprocal of 21561.

Palindrome?

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

The number 21561 is not a palindrome.

Not A Prime Number

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

Twenty-one thousand five hundred and sixty-one is a composite number with 4 total factors (including 1 and itself).   See primes in Base 10 Decimal

A Composite

Composites have more than just these two factors.

Twenty-one thousand five hundred and sixty-one is a composite number with 4 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 twenty-one thousand five hundred and sixty-one has the following 2 prime factors:

3
Three
7187
Seven Thousand One Hundred and Eighty-Seven

Prime Factorization

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

31 · 71871 = 21561

Base Conversions

The number twenty-one thousand five hundred and sixty-one in 35 different bases