Properties of the Number 19980

Nineteen Thousand Nine Hundred Eighty

Basics

Value: 19979 → 19980 → 19981

Parity: even

Prime: No

Previous Prime: 19979

Next Prime: 19991

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 2 ² × 3 ³ × 5 × 37

Divisors: 1, 2, 3, 4, 5, 6, 9, 10, 12, 15

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100111000001100

Octal: 47014

Duodecimal: B690

Hexadecimal: 4e0c

Square: 399200400

Square Root: 141.35062787267697

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

Number of ways to place 3 nonattacking knights on a 3 X n board. A172212

Number T(n,k) of parts in all proper k-times partitions of n; triangle T(n,k), n >= 1, 0 <= k <= n-1, read by rows. A327631

Number of ordered triples (w,x,y) with all terms in {1,...,n} and w³ >= x³ + y³. A211651

Composite numbers with properties that its digits (which may appear with multiplicity) may not appear in any of its factors (wherein the digits may also appear with multiplicity) and the combined digits of the product and the factors must have at least one of each of the ten digits. A370972

a(n) = 9973·n + 10007. A101442

Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 260", based on the 5-celled von Neumann neighborhood. A287285

Numbers k such that if you subtract k-reversed from k you get a natural number with the same digits as k. A121969

Triangle read by rows: T(n,k) (n >= 2, k >= 1) is the number of non-crossing connected graphs on n nodes on a circle such that the distance from a fixed node (root) to the next node is k. Rows are indexed 2,3,4,...; columns are indexed 1,2,3, ... . A143018

a(n) = ∑_k=0..n (n+k+2)!/((n-k)!*k!*2^k). A144513

a(n) = 1000·n - 20. A157515