Properties of the Number 21776

Twenty-One Thousand Seven Hundred Seventy-Six

Basics

Value: 21775 → 21776 → 21777

Parity: even

Prime: No

Previous Prime: 21773

Next Prime: 21787

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 2 ⁴ × 1361

Divisors: 1, 2, 4, 8, 16, 1361, 2722, 5444, 10888, 21776

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010100010000

Octal: 52420

Duodecimal: 10728

Hexadecimal: 5510

Square: 474194176

Square Root: 147.56693396557372

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(1) = 1 and a(n) = ceiling((∑_k=1..n-1 a(k))/3) for n >= 2. A72493

Polar structured meta-anti-diamond numbers, the n-th number from a polar structured n-gonal anti-diamond number sequence. A100188

Josephus problem: numbers m such that, when m people are arranged on a circle and numbered 1 through m, the final survivor when we remove every 4th person is one of the first three people. A5427

G.f. satisfies A(x) = 1 + x/A(x)²*(1 + 1/A(x)²). A364397

McKay-Thompson series of class 35A for Monster. A58640

Coordination sequence for σ-CrFe, Position Xc. A9961

Sum of distances of numbers between successive powers of 2 (beginning with 2¹) to previous numbers with same number of prime factors, repetitions included. See example. A176883

The numbers of people such that, in the variant of the Josephus problem in which three people are skipped and then one is eliminated, the first person is the last to be eliminated. A385327

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

Number of length n+6 0..3 arrays with at most two downsteps in every 6 consecutive neighbor pairs. A255658