Properties of the Number 815

Eight Hundred Fifteen

Basics

Value: 814 → 815 → 816

Parity: odd

Prime: No

Previous Prime: 811

Next Prime: 821

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 5 × 163

Divisors: 1, 5, 163, 815

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 1100101111

Octal: 1457

Duodecimal: 57B

Hexadecimal: 32f

Square: 664225

Square Root: 28.548204847240395

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

Toothpick sequence (see Comments lines for definition). A139250

a(n) = a(n-1) + a(n-2) + a(n-3), a(0)=3, a(1)=1, a(2)=3. A1644

Numbers whose binary expansion is a decimal prime. A36952

Numbers m such that the Bernoulli number B_2·m has denominator 66. A51229

Numbers n such that the number of squarefree numbers between prime(n) and prime(n+1) = prime(n+1)-prime(n)-1. A68361

Generalized 17-gonal (or heptadecagonal) numbers: m*(15·m - 13)/2 with m = 0, +1, -1, +2, -2, +3, -3, ... A303305

|First digit - second digit + third digit - fourth digit ...| = 12. A60980

A000120-perfect numbers. A175522

Triangle read by rows giving number of arrangements of k dumbbells on 2 X n grid (n >= 0, k >= 0). A46741

a(n) = 24·n - 1. A183010