Properties of the Number 27990

Twenty-Seven Thousand Nine Hundred Ninety

Basics

Value: 27989 → 27990 → 27991

Parity: even

Prime: No

Previous Prime: 27983

Next Prime: 27997

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 2 × 3 ² × 5 × 311

Divisors: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 110110101010110

Octal: 66526

Duodecimal: 14246

Hexadecimal: 6d56

Square: 783440100

Square Root: 167.30212192318422

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 connected 2-element antichains on a labeled n-set. A94033

Triangle read by rows: T(n, k) = (k+1)*S2(n+1, k+1), for n >= k >= 0, and S2 = A048993 (Stirling2). A321331

Worpitzky(n, k)*Harmonic(k), triangle read by rows. A176276

Number of n-node rooted identity trees with thinning limbs and root outdegree (branching factor) 4. A245123

Triangle T : T(n,k)= binomial(n,k)*A000957(n+1-k). A171616

Number of graphs on n labeled nodes with degree at most 3. A136282

Sum{T(n,k)*T(n,2n-k)}, 0<=k<=n, T given by A027926. A27990