Properties of the Number 27991

Twenty-Seven Thousand Nine Hundred Ninety-One

Basics

Value: 27990 → 27991 → 27992

Parity: odd

Prime: No

Previous Prime: 27983

Next Prime: 27997

Digit Sum: 28

Digital Root: 1

Palindrome: No

Factorization: 23 × 1217

Divisors: 1, 23, 1217, 27991

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 110110101010111

Octal: 66527

Duodecimal: 14247

Hexadecimal: 6d57

Square: 783496081

Square Root: 167.3051105017417

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

Numbers that have 10 terms in their Zeckendorf representation. A179250

Absolute discriminants of complex quadratic fields with 3-class group of type (3,3), 3-principalization type (4443), IPAD [(3,3,3)³, (3,9)], and Hilbert 3-class field tower of unknown length at least 3. A242873

a(n) = dot_product(1,2,...,n)*(7,8,...,n,1,2,3,4,5,6). A26049

Expansion of g.f. A(x) satisfying 1 = ∑_n=-oo..+oo xⁿ * (x^2·n - A(x))ⁿ. A358937

Number of two-rowed partitions of length 4. A70557

Number of connected 2-element multiantichains on a labeled n-set. A94734

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 515", based on the 5-celled von Neumann neighborhood. A272707

Absolute discriminants of complex quadratic fields with 3-class group of type (3,3) whose second 3-class group is located on the sporadic part of the coclass graph G(3,2) outside of coclass trees. A247691

a(n) = Sum{T(n,k)*T(n,2n-k)}, 0<=k<=n-1, T given by A027926. A27991

a(n) = 1 + 2·n² + 3·n³ + 4·n⁴ + 5·n⁵ + 6·n⁶ + 7·n⁷ + 8·n⁸. A209267