Properties of the Number 28721

Twenty-Eight Thousand Seven Hundred Twenty-One

Basics

Value: 28720 → 28721 → 28722

Parity: odd

Prime: No

Previous Prime: 28711

Next Prime: 28723

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 7 × 11 × 373

Divisors: 1, 7, 11, 77, 373, 2611, 4103, 28721

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 111000000110001

Octal: 70061

Duodecimal: 14755

Hexadecimal: 7031

Square: 824895841

Square Root: 169.47271166769002

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

(prime(n)*(prime(n+1)-1) + (prime(n)-1)*prime(n+1)) / 2. A99909

Primitive solutions k to k² = u⁴ + v⁴ + w⁴, with u, v, w > 0. A365688

Minimum power to which 2 must be raised so that the first n digits of the result are the digits of A155699(n). A155700

Number of n X 2 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4. A239852

Integers k such that k² can be written as the sum of three positive fourth powers. A365657

tanh(tan(x)+sin(x))=2·x-15/3!*x³+449/5!*x⁵-28721/7!*x⁷... A12943

Numbers k such that sopf(k)*nud(k) = π(k), where sopf(k)=A008472, nud(k)=A034444 and π(k)=A000720. A64015

Expansion of x*(2-4·x²-x³)/((1-x)²*(1-x-x²)). A133931

Expansion of (theta₃(z)*theta₃(7z)*theta₃(49z)+theta₂(z)*theta₂(7z)*theta₂(49z))⁴. A28721

Number of (n+1)X(2+1) 0..2 arrays with the maximum plus the upper median minus the minimum of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one. A237505