Properties of the Number 23821

Twenty-Three Thousand Eight Hundred Twenty-One

Basics

Value: 23820 → 23821 → 23822

Parity: odd

Prime: No

Previous Prime: 23819

Next Prime: 23827

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 7 × 41 × 83

Divisors: 1, 7, 41, 83, 287, 581, 3403, 23821

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101110100001101

Octal: 56415

Duodecimal: 11951

Hexadecimal: 5d0d

Square: 567440041

Square Root: 154.34053258946594

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

Square pyramidal numbers: a(n) = 0² + 1² + 2² + ... + n² = n*(n+1)*(2·n+1)/6. A330

Structured rhombic dodecahedral numbers (vertex structure 9). A100157

1/24 of product of three numbers: n-th prime, previous and following number. A127922

a(0)=0; then a(4·k+1)=a(4·k)+(4·k+1)², a(4·k+2)=a(4·k+1)+(4·k+3)², a(4·k+3)=a(4·k+2)+(4·k+2)², a(4·k+4)=a(4·k+3)+(4·k+4)². A115391

a(n) = 7·n*(2·n + 1). A195026

The number of binary pattern classes in the (2,n)-rectangular grid with 3 '1's and (2n-3) '0's: two patterns are in same class if one of them can be obtained by a reflection or 180-degree rotation of the other. A225972

E.g.f. satisfies A(x) = exp( x / (1 - x·A(x))³ ). A364938

a(n) = s(1)*s(n) + s(2)*s(n-1) + ... + s(k)*s(n+1-k), where k = floor((n+1)/2), s = (odd natural numbers). A24598

Number of (w,x,y,z) with all terms in {1,...,n} and w > harmonic mean of {x,y,z}. A212105

Odd square pyramidal numbers. A15221