Properties of the Number 20860

Twenty Thousand Eight Hundred Sixty

Basics

Value: 20859 → 20860 → 20861

Parity: even

Prime: No

Previous Prime: 20857

Next Prime: 20873

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 2 ² × 5 × 7 × 149

Divisors: 1, 2, 4, 5, 7, 10, 14, 20, 28, 35

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000101111100

Octal: 50574

Duodecimal: 100A4

Hexadecimal: 517c

Square: 435139600

Square Root: 144.4299137990465

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) = (n+1)*(n²+n+2)/2; g.f.: (1 + 2·x²) / (1 - x)⁴. A6000

a(n) = 3·a(n-2) - a(n-3) with a(0)=-1, a(1)=1, a(2)=-4. A214779

a(n) = floor( tan(m*π/2) ), where m = 1 - 2^-n. A24810

Relative of Hofstadter Q-sequence: a(n) = max(0, n+20830) for n <= 0; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 0. A283887

The fifth term of the greedy B_n set of natural numbers. A369817

Cubes written in base 9. A4639

Engel expansion for tan(1). A84652

Elements of A065607 from primitive triples. A120693

Number of d+/d- diagonally convex polyominoes with n cells. A187276

Number of words of length 2n in the 10 transpositions of S[5] equivalent to the identity. A29698