Properties of the Number 28912

Twenty-Eight Thousand Nine Hundred Twelve

Basics

Value: 28911 → 28912 → 28913

Parity: even

Prime: No

Previous Prime: 28909

Next Prime: 28921

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 2 ⁴ × 13 × 139

Divisors: 1, 2, 4, 8, 13, 16, 26, 52, 104, 139

Polygonal

Triangular: No

Square: No

Pentagonal: Yes

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 111000011110000

Octal: 70360

Duodecimal: 14894

Hexadecimal: 70f0

Square: 835903744

Square Root: 170.03529045465825

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..2 arrays with the maximum plus the minimum of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one. A237234

E.g.f.: exp( ∑_n>=1 Fibonacci(n)*xⁿ/n ). A244430

Pentagonal numbers with prime indices. A116995

G.f. satisfies: A(x) = ∏_n>=1 (1+xⁿ)*(1 + xⁿ*A(x))/((1-xⁿ)*(1 - xⁿ*A(x))). A192624

Pentagonal numbers that are abundant. A379264

Aliquot sequence starting at 702. A269542

Number of (n+1) X (1+1) 0..2 arrays with the maximum plus the minimum of every 2 X 2 subblock differing from its horizontal and vertical neighbors by exactly one. A237227

Number of (n+1) X (6+1) 0..2 arrays with the maximum plus the minimum of every 2 X 2 subblock differing from its horizontal and vertical neighbors by exactly one. A237232

Pentagonal numbers divisible by 4. A298397

Pentagonal numbers for which the sum of the digits is also a pentagonal number. A117709