Properties of the Number 19520

Nineteen Thousand Five Hundred Twenty

Basics

Value: 19519 → 19520 → 19521

Parity: even

Prime: No

Previous Prime: 19507

Next Prime: 19531

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 2 ⁶ × 5 × 61

Divisors: 1, 2, 4, 5, 8, 10, 16, 20, 32, 40

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100110001000000

Octal: 46100

Duodecimal: B368

Hexadecimal: 4c40

Square: 381030400

Square Root: 139.71399357258383

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

a(n) = ∑_{i=1..n, j=1..n, gcd(i,j)=1} (n+1-i)*(n+1-j). A115004

Numbers whose product of prime indices is twice their sum of prime indices. A326151

First row of spectral array W(sqrt(5)-1). A22165

Fibonacci sequence beginning 0, 32. A22366

Let (u1,u2) be successive untouchable numbers such that φ(u1) = φ(u2); sequence gives values of u2. A48190

Triangular array: the fission of ((x+2)ⁿ) by (q(n,x)) given by q(n,x)=xⁿ+x^n-1+...+x+1. A193850

Mirror of the triangle A193850. A193851

a(n) = φ(A291789(n)). A291805

Define the sequence S(a(0),a(1)) by a(n+2) is the least integer such that a(n+2)/a(n+1) > a(n+1)/a(n) for n >= 0. This is S(1,5). A18903

Consider all integer triples (i,j,k), j >= k > 0, with binomial(i+2,3) = j³ + k³, ordered by increasing i; sequence gives i values. A54205