Properties of the Number 21881

Twenty-One Thousand Eight Hundred Eighty-One

Basics

Value: 21880 → 21881 → 21882

Parity: odd

Prime: Yes

Previous Prime: 21871

Next Prime: 21893

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 21881

Divisors: 1, 21881

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010101111001

Octal: 52571

Duodecimal: 107B5

Hexadecimal: 5579

Square: 478778161

Square Root: 147.92227688891217

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 form n² + 10000. A256838

Primes p whose reciprocal has period (p-1)/10. A56215

Primes p such that A001175(p) = (p-1)/4. A308789

Number of magic labelings with magic sum n of first graph shown in link. A244869

Sum of the third largest parts in the partitions of n into 7 parts. A308931

Primes having only {1, 2, 8} as digits. A385775

Starting index of a string of exactly 4 consecutive equal digits in decimal expansion of π. A49520

Starting index of a string of 4 or more consecutive equal digits in decimal expansion of π. A49516

Middle of 3 consecutive prime numbers, p1, p2, p3, such that p1·p2·p3·d1·d2 = average of twin prime pairs; d1 (δ) = p2 - p1, d2 (δ) = p3 - p2. A153410

The number of simple permutations of length n in a particular geometric grid class. A226432