The Number

21001

Twenty-One Thousand and One

Nearby Numbers

Positive, nonzero integers within three units

20998
Twenty Thousand Nine Hundred and Ninety-Eight
20999
Twenty Thousand Nine Hundred and Ninety-Nine
21000
Twenty-One Thousand
21002
Twenty-One Thousand and Two
21003
Twenty-One Thousand and Three
21004
Twenty-One Thousand and Four

Scientific Notation

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

2.1001e4

Reciprocal

A number multiplied with its reciprocal is one.

0.000047616780153326035

The reciprocal of 21001.

Palindrome?

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

The number 21001 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 and one is the 2361st prime number.   See primes in Base 10 Decimal

Not A Composite

Composites have more than just these two factors.

Twenty-One Thousand and One is not a composite number because it has exactly two factors: One and Twenty-One Thousand and 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 and one has the following 1 prime factor:

21001
Twenty-One Thousand and One

Prime Factorization

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

210011 = 21001

Base Conversions

The number twenty-one thousand and one in 35 different bases