Properties of the Number 1989

One Thousand Nine Hundred Eighty-Nine

Basics

Value: 1988 → 1989 → 1990

Parity: odd

Prime: No

Previous Prime: 1987

Next Prime: 1993

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 13 × 17

Divisors: 1, 3, 9, 13, 17, 39, 51, 117, 153, 221

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11111000101

Octal: 3705

Duodecimal: 1199

Hexadecimal: 7c5

Square: 3956121

Square Root: 44.598206241955516

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

Partial sums of primes, if 1 is regarded as a prime (as it was until quite recently, see A008578). A14284

Generalized 24-gonal (or icositetragonal) numbers: m*(11·m - 10) with m = 0, +1, -1, +2, -2, +3, -3, ... A303814

Numbers which are the sum of one or more consecutive nonnegative cubes. A217843

Total number of toothpicks in the toothpick structure A139250 that are parallel to the initial toothpick, after n odd rounds. A162795

Numbers m such that m and m+1 are consecutive lazy-Fibonacci-Niven numbers (A328212). A328213

a(n) = n*(n + 12). A98847

Numbers where 9 outnumbers any other digit. A292449

a(n) = 90·n - 81. A139280

Number of integer compositions of n that are not the first sums of any composition. A391680

Array read by antidiagonals: T(n,k) = number of nonequivalent dissections of a polygon into n k-gons by nonintersecting diagonals up to rotation (k >= 3). A295224