Properties of the Number 42520

Forty-Two Thousand Five Hundred Twenty

Basics

Value: 42519 → 42520 → 42521

Parity: even

Prime: No

Previous Prime: 42509

Next Prime: 42533

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 2 ³ × 5 × 1063

Divisors: 1, 2, 4, 5, 8, 10, 20, 40, 1063, 2126

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

4823 Try Today's Challenge

Representations

Binary: 1010011000011000

Octal: 123030

Duodecimal: 20734

Hexadecimal: a618

Square: 1807950400

Square Root: 206.20378270051208

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

T(n,k)=Number of (n+1)X(k+1) 0..3 arrays containing all values 0..3 with every 2X2 subblock having three distinct values, and new values 0..3 introduced in row major order. A210267

Number of Dyck paths of semilength n having no DUDU's starting at level 1. A135339

Least number k such that (n!+k)/n and (n!-k)/n are both prime. A245697

Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having k DUDU's starting at level 1. A135333

Number of nX6 0..4 arrays with each element equal to the number its horizontal and vertical neighbors equal to 2. A197059

Number of (n+1) X 2 0..3 arrays containing all values 0..3 with every 2 X 2 subblock having three distinct values, and new values 0..3 introduced in row major order. A210260

Number of (n+1)X6 0..3 arrays containing all values 0..3 with every 2X2 subblock having three distinct values, and new values 0..3 introduced in row major order. A210264

a(n) = ∑_k=1..n k*[ (n/k)*[ (n/k)*[ n/k ] ] ]. A24933

a(n) is the smallest k such that σ(σ(k)) = σ(σ(k) - k) + n·k, or 0 if no such k exists. A292413

T(n,k) = number of defective 4-colorings of an n X k 0..3 array connected horizontally, vertically, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..3 order. A229578