Properties of the Number 7865

Seven Thousand Eight Hundred Sixty-Five

Basics

Value: 7864 → 7865 → 7866

Parity: odd

Prime: No

Previous Prime: 7853

Next Prime: 7867

Digit Sum: 26

Digital Root: 8

Palindrome: No

Factorization: 5 × 11 ² × 13

Divisors: 1, 5, 11, 13, 55, 65, 121, 143, 605, 715

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1111010111001

Octal: 17271

Duodecimal: 4675

Hexadecimal: 1eb9

Square: 61858225

Square Root: 88.68483523128404

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

Preperiod (or threshold) of orbit of Post's {00, 1101} tag system applied to the word (100)ⁿ, or -1 if this word has an unbounded trajectory. A284119

Triangle read by rows: T(n,k) = number of arrangements of n indistinguishable balls in n boxes with the maximum number of balls in any box equal to k. A180281

Numbers m such that there are precisely 7 groups of order m. A249550

Numbers whose square can be represented in exactly two ways as the sum of a positive square and a positive fourth power. A345700

Number of n-variations of the set {1,2,...,n+1} satisfying p(i)-i in {-2,0,2}, i=1..n (an n-variation of the set N_n+s = {1,2,...,n+s} is any 1-to-1 mapping p from the set N_n = {1,2,...,n} into N_n+s = {1,2,...,n+s}). A217694

Numbers k for which A276086(A003415(k)) is a multiple of k, where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function. A370114

Numbers that can be written in exactly two different ways as s₁^x_1 + ... + s_t^x_t, with 1 < s₁ < ... < s_t and {s₁,..., s_t} = {x₁,..., x_t} for some t > 0. A386966

Vertex number of a rectangular spiral related to prime numbers. The distances between nearest edges of the spiral that are parallel to the initial edge are the prime numbers, while the distances between nearest edges perpendicular to the initial edge are all one. A160792

Triangle V(l,p) (l>=0, p=0..l) read by rows: see Formula for definition, see Comments for motivation. A179898

a(n) = ∑_i=0..n digsum₅(i)³, where digsum₅(i) = A053824(i). A231670