Properties of the Number 28009

Twenty-Eight Thousand Nine

Basics

Value: 28008 → 28009 → 28010

Parity: odd

Prime: No

Previous Prime: 28001

Next Prime: 28019

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 37 × 757

Divisors: 1, 37, 757, 28009

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 110110101101001

Octal: 66551

Duodecimal: 14261

Hexadecimal: 6d69

Square: 784504081

Square Root: 167.35889578985635

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

Pseudoprimes to base 3. A5935

Euler pseudoprimes to base 3: composite integers such that abs(3^{(n - 1}/2)) == 1 mod n. A262051

Base-3 Euler-Jacobi pseudoprimes. A48950

Numerators of central difference coefficients M₃²ⁿ⁺¹. A2673

T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with no 3x3 subblock diagonal sum 2 and no antidiagonal sum 2 and no row sum 0 and no column sum 0. A255792

Composite numbers k == 1, 11 (mod 12) such that 3^(k-1/2) == 1 (mod k). A375917

T(n,k)=Number of nXk 0..5 arrays with values 0..5 introduced in row major order and each element equal to at least one horizontal or vertical neighbor. A198627

Strong pseudoprimes to base 9. A20235

Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=2, I={0,1}. A80013

Terms of A122780 which are not Carmichael numbers A002997. A153514