Properties of the Number 20471

Twenty Thousand Four Hundred Seventy-One

Basics

Value: 20470 → 20471 → 20472

Parity: odd

Prime: No

Previous Prime: 20443

Next Prime: 20477

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 11 × 1861

Divisors: 1, 11, 1861, 20471

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100111111110111

Octal: 47767

Duodecimal: BA1B

Hexadecimal: 4ff7

Square: 419061841

Square Root: 143.0769023986751

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

Floor(X/Y) where X = concatenation of the (n+1)-st even number through the (2n)-th even number and Y = concatenation of first n even numbers. A67091

G.f.: exp( ∑_n>=1 A174466(n)*xⁿ/n ) where A174466(n) = ∑_d∣n d*σ(n/d)*τ(d). A174465

a(n) = 10·2^n-1 - 9. A139634

Number of distinct values of ∑_i=0..n x(i)*binomial(n,i), where the x(i) have values in 0..5. A205540

a(n) = n + (n-1)*(2ⁿ-2). A188716

G.f. A(x) satisfies A(x)³ = A(x³) / (1 - 3·x)³ with A(0)=1. A372870

a(n) = 169·n² + 2·n. A158220

Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 13. A31691

Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..2 n X 2 array. A219621

a(n) is the least number that can be written in exactly n ways as p·q + q·r + p·r where (p,q,r) is an unordered triple of distinct primes. A356457