Properties of the Number -2009

Nine

Basics

Value: -2010 → -2009 → -2008

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 11

Digital Root: 2

Palindrome: No

Factorization: 7 ² × 41

Divisors: 1, 7, 41, 49, 287, 2009

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: -11111011001

Octal: -3731

Duodecimal: -11B5

Hexadecimal: -7d9

Square: 4036081

Square Root: 44.82186966202994

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

Coefficient array of orthogonal polynomials P(n,x)=(x-n)*P(n-1,x)-(n-1)²*P(n-2,x), P(0,x)=1, P(1,x)=x-1. A182823

Sum of all parts of all partitions of n into an even number of parts minus the sum of all parts of all partitions of n into an odd number of parts. A235324

Odd numbers of the form p^1+4k * r², where p is prime of the form 1+4m, r > 1, and gcd(p,r) = 1. (Euler's criteria for odd perfect numbers). A228058

Number of subsets of {1, 2, ..., n} such that no member is a sum of distinct other members. A151897

a(n) = n*(n+8). A28566

Numerator of 1/16 - 1/n². A61041

Expansion of b(2)*b(4)*b(6)/(x⁸-x⁴-x+1), where b(k) = (1-x^k)/(1-x). A265055

Number of increasing arithmetic progressions in {1,2,3,...,n}, including trivial arithmetic progressions of lengths 1 and 2. A51336

Triangle read by rows: T(n,d) is the number of distinct properly d-dimensional polyominoes (or polycubes) with n cells (n >= 1, d >= 0). A49430

Numbers k such that p(k), p(k)+6, p(k)+12, p(k)+18 are consecutive primes, where p(k) denotes k-th prime. A90832