Properties of the Number 21000

Twenty-One Thousand

Basics

Value: 20999 → 21000 → 21001

Parity: even

Prime: No

Previous Prime: 20983

Next Prime: 21001

Digit Sum: 3

Digital Root: 3

Palindrome: No

Factorization: 2 ³ × 3 × 5 ³ × 7

Divisors: 1, 2, 3, 4, 5, 6, 7, 8, 10, 12

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

4823 Try Today's Challenge

Representations

Binary: 101001000001000

Octal: 51010

Duodecimal: 101A0

Hexadecimal: 5208

Square: 441000000

Square Root: 144.9137674618944

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Numbers whose sum of digits is 3. A52217

Triangle T(n,k) = k! * Stirling1(n,k), 1<=k<=n. A48594

Even octagonal numbers: a(n) = 4·n*(3·n-1). A14642

Triangle of coefficients of certain polynomials (exponents in decreasing order). A33842

11-gonal (or hendecagonal) pyramidal numbers: a(n) = n*(n+1)*(3·n-2)/2. A7586

Numbers m that raised to the powers from 1 to k (with k>=1) are multiple of the sum of their digits (m raised to k+1 must not be a multiple). Case k=16. A135201

A partition product of Stirling₁ type [parameter k = 4] with biggest-part statistic (triangle read by rows). A157394

Triangle read by rows, the ordered Stirling cycle numbers, T(n, k) = k!* s(n, k); n >= 0 k >= 0. A225479

Coefficients of certain polynomials (rising powers). A75181

A partition product of Stirling₂ type [parameter k = -4] with biggest-part statistic (triangle read by rows). A157398