Properties of the Number 21841

Twenty-One Thousand Eight Hundred Forty-One

Basics

Value: 21840 → 21841 → 21842

Parity: odd

Prime: Yes

Previous Prime: 21839

Next Prime: 21851

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 21841

Divisors: 1, 21841

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

4823 Try Today's Challenge

Representations

Binary: 101010101010001

Octal: 52521

Duodecimal: 10781

Hexadecimal: 5551

Square: 477029281

Square Root: 147.78700890132393

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

Primes of the form j² + (j+1)². A27862

Primes which can be expressed as sum of distinct powers of 4. A77718

Largest prime factor of 8ⁿ + 1. A274905

Third row of Pascal-(1,5,1) array A081580. A81589

Centered 28-gonal numbers. A195314

E.g.f. exp(x+x⁴). A190875

Primes that become squares when prefixed with a 2. A167735

Primes p such that A001177(p) = (p-1)/6. A308799

Primes of the form (4·n²-8·n-9)/3. A154616

Hypotenuse C of primitive Pythagorean triangles such that perimeters are Averages of twin prime pairs, q=p+1, a=q²-p², c=q²+p², b=2·p*q, s=a+b+c, s-+1 are primes. A155175