Properties of the Number 8721

Eight Thousand Seven Hundred Twenty-One

Basics

Value: 8720 → 8721 → 8722

Parity: odd

Prime: No

Previous Prime: 8719

Next Prime: 8731

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ³ × 17 × 19

Divisors: 1, 3, 9, 17, 19, 27, 51, 57, 153, 171

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

8509 Try Today's Challenge

Representations

Binary: 10001000010001

Octal: 21021

Duodecimal: 5069

Hexadecimal: 2211

Square: 76055841

Square Root: 93.38629449764028

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

4-dimensional pyramidal numbers: a(n) = n²*(n²-1)/12. A2415

a(n) = 10·a(n-1) - a(n-2) for n > 1, a(0) = a(1) = 1. A72256

Every run of digits of n in base 16 has length 2. A33014

Sum of the smallest parts of the partitions of 4n into 4 parts. A238702

Numbers k such that k² is a sum of consecutive cubes larger than 1. A126200

3ⁿ with digits rearranged into nonincreasing order. A321539

a(n) = A054320(n) - A001078(n). A138288

Numbers n such that n² can be represented as sum of (at least two) consecutive cubes and n is not a triangular number. A163393

a(n) = A000422(n)^^A000422(n) (mod 10^len(A000422(n))), where ^^ indicates tetration or hyper-4 (e.g., 3^⁴ = 3^{3^(3³})). A317824

Numbers k > 1 such that, in base 4, k and k² contain the same digits in the same proportion. A61658