Properties of the Number 8128

Eight Thousand One Hundred Twenty-Eight

Basics

Value: 8127 → 8128 → 8129

Parity: even

Prime: No

Previous Prime: 8123

Next Prime: 8147

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 ⁶ × 127

Divisors: 1, 2, 4, 8, 16, 32, 64, 127, 254, 508

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

Today's Target

8509 Try Today's Challenge

Representations

Binary: 1111111000000

Octal: 17700

Duodecimal: 4854

Hexadecimal: 1fc0

Square: 66064384

Square Root: 90.15542135667715

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: Yes

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

Perfect numbers k: k is equal to the sum of the proper divisors of k. A396

Multiply-perfect numbers: n divides σ(n). A7691

a(n) = 2^n-1*(2ⁿ - 1), n >= 0. A6516

Harmonic or Ore numbers: numbers k such that the harmonic mean of the divisors of k is an integer. A1599

Centered 9-gonal (also known as nonagonal or enneagonal) numbers. Every third triangular number, starting with a(1)=1. A60544

Triangular numbers (A000217) with prime indices. A34953

Numbers whose abundancy index is a power of 2. A336702

G.f.: q * ∏_m>=1 (1-q^m)⁸*(1-q^2m)⁸. A2288

Sum of every 4th entry of row n in Pascal's triangle, starting at "n choose 1". A38504

a(n) = 2·n*(4·n - 1). A14635