Properties of the Number -1905

Nine Hundred Five

Basics

Value: -1906 → -1905 → -1904

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 5 × 127

Divisors: 1, 3, 5, 15, 127, 381, 635, 1905

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -11101110001

Octal: -3561

Duodecimal: -1129

Hexadecimal: -771

Square: 3629025

Square Root: 43.64630568559039

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

G.f.: ∑_n=-oo..+oo x^n*(n+1/2) * C(x)^3·n-3, where C(x) = 1 + x·C(x)² is the g.f. of the Catalan numbers (A000108). A355348

Triangle read by rows: T(n,0) = n+1, T(n,k) = 2·T(n-1,k) - T(n-1,k-1), T(n,k) = 0 if k > n and if k < 0. A159856

Riordan array T((1-x)^-2 | 2x-1) read by rows. A181690

Alternating sum of 11-gonal (or hendecagonal) numbers. A266087

First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 483", based on the 5-celled von Neumann neighborhood. A272346

Expansion of e.g.f. arcsinh(arctan(x) + log(x+1)). A12966

Expansion of e.g.f. arcsinh(tanh(x) + log(x+1)). A13124

Fermat pseudoprimes to base 2, also called Sarrus numbers or Poulet numbers. A1567

Arithmetic derivative of the primorial base exp-function: a(n) = A003415(A276086(n)). A327860

Number of integer partitions of n whose product of parts is >= n. A319005