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Properties of the Number -2145

One Hundred Forty-Five

Basics

Value: -2146 → -2145 → -2144

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 3 × 5 × 11 × 13

Divisors: 1, 3, 5, 11, 13, 15, 33, 39, 55, 65

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

Today's Target

5184 Try Today's Challenge

Representations

Binary: -100001100001

Octal: -4141

Duodecimal: -12A9

Hexadecimal: -861

Square: 4601025

Square Root: 46.314144707637645

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

Numerators of triangle S(n,k), n>=0, 0<=k<=ceiling((3n+1)/2): S(n,k) is the coefficient of xk in polynomial sn(x), used to define continuous and n times differentiable sigmoidal transfer functions. A144702
Numerators of triangle T(n,k), n>=0, 0<=k<=n, read by rows: T(n,k) is the coefficient of x2k+1 in polynomial tn(x), used to define continuous and n times differentiable sigmoidal transfer functions. A144815
Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of min{2i+j,i+2j} (A204002). A204003
Expansion of e.g.f. theta3-11/2. A15687
Triangular table of numerators of the coefficients of Laguerre-Sonin polynomials L(1/2,n,x). A131440
a(n) is the product of all parts in negaFibonacci representation of -n. A356388
Hexagonal numbers: a(n) = n*(2·n-1). A384
The squarefree numbers ordered lexicographically by their prime factorization (with factors written in decreasing order). a(n) = ∏k in I prime(k+1), where I is the set of indices of nonzero binary digits in n = ∑k in I 2k. A19565
Tritriangular numbers: a(n) = binomial(binomial(n,2),2) = n*(n+1)*(n-1)*(n-2)/8. A50534
Triangle of Bessel numbers read by rows: T(n,k) is the number of k-matchings of the complete graph K(n). A100861