Properties of the Number 28440

Twenty-Eight Thousand Four Hundred Forty

Basics

Value: 28439 → 28440 → 28441

Parity: even

Prime: No

Previous Prime: 28439

Next Prime: 28447

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 ³ × 3 ² × 5 × 79

Divisors: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 110111100011000

Octal: 67430

Duodecimal: 14560

Hexadecimal: 6f18

Square: 808833600

Square Root: 168.64163187066237

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 arrangements of n+1 nonzero numbers x(i) in -k..k with the sum of trunc(x(i)/x(i+1)) equal to zero. A189545

T(n,k)=Number of nXnXn triangular 0..k arrays with some element plus some adjacent element totalling k+1, k or k-1 exactly once. A270850

Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-fifth of 1s, 2s, 3s, 4s and 5s (ordered occurrences rounded up/down if n·m ≠ 0 mod 5). A287021

a(n) = 1·2*3·4*5·6*7·8 - 9·10·11·12·13·14·15·16 + 17·18·19·20·21·22·23·24 - ... + (up to n). A319549

T(n,k) = Half the number of n X k binary arrays with the number of 1-1 horizontal, vertical, diagonal and antidiagonal adjacencies equal to the number of 0-0 adjacencies. A183289

Number of permutations of [n] such that the number of cycles of length k is zero or a divisor of k for every k. A374292

Nine times hexagonal numbers: a(n) = 9·n*(2·n-1). A152994

McKay-Thompson series of class 16A for Monster. A58514

Solutions k of the equation isigma(k) = isigma(k-1) + isigma(k-2) where isigma(k) is the sum of the infinitary divisors of k (A049417). A332975

Triangle read by rows: T(n,m)=A060187(1+n,1+m) *n! / (n-m)! A177429