Properties of the Number -845

Eight Hundred Forty-Five

Basics

Value: -846 → -845 → -844

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 5 × 13 ²

Divisors: 1, 5, 13, 65, 169, 845

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

8509 Try Today's Challenge

Representations

Binary: -1101001101

Octal: -1515

Duodecimal: -5A5

Hexadecimal: -34d

Square: 714025

Square Root: 29.068883707497267

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

Coefficients of the 3rd-order mock θ function f(q). A25

Coefficient of q²ⁿ in the series expansion of Ramanujan's mock θ function f(q). A39

Triangle T(n, k) = ∏_j=1..k ∏_i=0..j-1 ( 1 - (n-k+1)*(3·i-2) ) with T(n, 0) = 1 and T(n, n) = n!, read by rows. A156730

a(n) = ∑_k=1..n (-1)^k-1 * binomial(k+2,3) * floor(n/k). A366938

First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 371", based on the 5-celled von Neumann neighborhood. A271457

The unique sequence such that ∑_d∣n d·a(d)^n/d = σ(n)² for every n. A383614

Odd numbers of the form p^1+4k * r², where p is prime of the form 1+4m, r > 1, and gcd(p,r) = 1. (Euler's criteria for odd perfect numbers). A228058

Sequence and first differences (A030124) together list all positive numbers exactly once. A5228

a(n) = 4*(n+1)*n + 5. A78370

Coordination sequence for "ubt" 3D uniform tiling. A299291