Properties of the Number 9905

Nine Thousand Nine Hundred Five

Basics

Value: 9904 → 9905 → 9906

Parity: odd

Prime: No

Previous Prime: 9901

Next Prime: 9907

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 5 × 7 × 283

Divisors: 1, 5, 7, 35, 283, 1415, 1981, 9905

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011010110001

Octal: 23261

Duodecimal: 5895

Hexadecimal: 26b1

Square: 98109025

Square Root: 99.5238664843765

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 compositions of n whose run-lengths are either weakly increasing or weakly decreasing. A332835

Triangle T(n,k) = number of forests of labeled rooted trees of height at most 1, with n labels, k of which are used for root nodes and any root may contain >= 1 labels, n >= 0, 0<=k<=n. A143396

Positions of ones in A264977; positions of twos in A277330. A277701

Numbers k such that τ(k) = τ(k+1) mod 691, where τ is Ramanujan's τ function A000594. A121733

a(n) = n*(8·n+3). A139276

Partial sums of A000132. A175360

Fundamental discriminants d uniquely characterizing all complex biquadratic fields Q(sqrt(-3),sqrt(d)) which have 3-class group of type (3,3) and second 3-class group isomorphic to SmallGroup(729,34). A250241

G.f. A(x) satisfies: A(x·R(x)) = x² + x³ where A(R(x)) = x. A350431

Sums of p-th to the q-th prime where p and q are consecutive primes. A114381

Trajectory of initial value 89 under iterations of the map A352544: half if even, add largest anagram if odd. A352542