Properties of the Number 20581

Twenty Thousand Five Hundred Eighty-One

Basics

Value: 20580 → 20581 → 20582

Parity: odd

Prime: No

Previous Prime: 20563

Next Prime: 20593

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 11 × 1871

Divisors: 1, 11, 1871, 20581

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000001100101

Octal: 50145

Duodecimal: BAB1

Hexadecimal: 5065

Square: 423577561

Square Root: 143.46079603849967

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

4th elementary symmetric function of the first n+3 primes. A24449

Triangle of T(n,k) coefficients of polynomials with first n prime numbers as roots. A70918

Number of monic polynomials with integer coefficients of degree n with all roots in unit disc. A51894

Principal diagonal of the convolution array A213771. A213772

Triangle read by rows: T(n,k) is coefficient of x^n-k in consecutive prime rooted polynomial of degree n, P(x) = ∏_k=1..n (x-p(k)) = 1·xⁿ + T(n,1)*x^n-1+ ... + T(n,k-1)*x + T(n,k), for 1 <= k <= n. A238146

Triangle read by rows: T(n, k) = coefficient of x^n-k in ∏_m=1..n (x+prime(m)); 0 <= k <= n, n >= 0. A260613

Leading term of n-th row of A081491. A81490

Number of n X 1 0..2 arrays avoiding the patterns z z+1 z or z z-1 z in any row or column. A207008

Triangle T(n,k) read by rows: coefficients of polynomials P_n(t) defined in Formula section. A287030

E.g.f. C(x) satisfies: A(x)² + B(x)² = C(x)², such that C'(x) = C(x) + 2·A(x)*B(x). A292183