Properties of the Number -55

Fifty-Five

Basics

Value: -56 → -55 → -54

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 10

Digital Root: 1

Palindrome: Yes

Factorization: 5 × 11

Divisors: 1, 5, 11, 55

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: Yes

Tetrahedral: No

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Representations

Binary: -110111

Octal: -67

Duodecimal: -47

Hexadecimal: -37

Square: 3025

Square Root: 7.416198487095663

Classification

Fibonacci: Yes

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

a(n) = 2 - n. A22958

a(n+2) = -a(n+1) + a(n) (signed Fibonacci numbers) with a(-2) = a(-1) = 1; or Fibonacci numbers (A000045) extended to negative indices. A39834

Triangle read by rows: lower triangular matrix which is inverse to Pascal's triangle (A007318) regarded as a lower triangular matrix. A130595

Nonzero coefficients of the Swiss-Knife polynomials for the computation of Euler, tangent, and Bernoulli numbers (triangle read by rows). A153641

a(n) = A003961(n) - 2·n. A252748

First term of n-th difference sequence of (floor(k·r)), r = sqrt(2), k >= 0. A325664

Signed Fibonomial triangle. A55870

Carlitz-Riordan q-Catalan numbers (recurrence version) for q=-4. A15099

a(n) = n*(-1)ⁿ. A38608

Expansion of e.g.f. 1 / (1 - x·cos(x)). A352252