Properties of the Number 20705

Twenty Thousand Seven Hundred Five

Basics

Value: 20704 → 20705 → 20706

Parity: odd

Prime: No

Previous Prime: 20693

Next Prime: 20707

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 5 × 41 × 101

Divisors: 1, 5, 41, 101, 205, 505, 4141, 20705

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000011100001

Octal: 50341

Duodecimal: BB95

Hexadecimal: 50e1

Square: 428697025

Square Root: 143.8923208513922

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

Expansion of (1 + x² - sqrt( 1 - 4·x + 2·x² + x⁴)) / (2·x) in powers of x. A82582

Lucas-Carmichael numbers: squarefree composite numbers k such that p | k => p+1 | k+1. A6972

Number T(n,k) of Dyck paths of semilength n having exactly k (possibly overlapping) occurrences of the consecutive step pattern given by the binary expansion of n, where 1=U=(1,1) and 0=D=(1,-1); triangle T(n,k), n>=0, read by rows. A243752

Numbers k such that k³ divides 4^k² + 1. A128678

Lucas-Carmichael numbers with 3 prime factors. A216925

Number of Dyck paths of semilength n with no DDUU. A86581

Generalized Catalan numbers A(x)² -(1+x)²*A(x) +x*(2+x+x²) =0. A25242

a(n) = numerator of sum of reciprocals of the terms of the continued fraction for H(n) = ∑_k=1..n 1/k. A112286

Odd composite integers m such that A087130(m) == 5 (mod m). A335671

Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n and having k DDUU's, where U=(1,1), D=(1,-1) (0<=k<=floor(n/2)-1 for n>=2). A114492