Properties of the Number 42840

Forty-Two Thousand Eight Hundred Forty

Basics

Value: 42839 → 42840 → 42841

Parity: even

Prime: No

Previous Prime: 42839

Next Prime: 42841

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 ³ × 3 ² × 5 × 7 × 17

Divisors: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1010011101011000

Octal: 123530

Duodecimal: 20960

Hexadecimal: a758

Square: 1835265600

Square Root: 206.97825972792407

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*(n-1)*(n-2) (or n!/(n-3)!). A7531

Triangle of numbers related to triangle A049375; generalization of Stirling numbers of second kind A008277, Lah-numbers A008297... A49385

Triangle read by rows: T(n,k) = number of closed meander systems of order n with k<=n components. A8828

Square roots of products of members of groups in A076031. A76030

Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(1,1), d=(1,-2) and have k peaks (i.e., ud's). A108767

Numbers n such that the multiplicative group modulo n is the direct product of 6 cyclic groups. A272596

Numbers expressible as (a²-1)(b²-1) in at least 2 distinct ways (b>=a>1). A63067

a(n) = (2·n+2)*(2·n+3)*(2·n+4) = 24·A000330(n+1). A69074

Triangle read by rows: T(n,k) = number of nonequivalent dissections of an n-gon into k polygons by nonintersecting diagonals up to rotation. A295633

Numbers k such that φ(k) = τ(k)². A68560