Properties of the Number 21775

Twenty-One Thousand Seven Hundred Seventy-Five

Basics

Value: 21774 → 21775 → 21776

Parity: odd

Prime: No

Previous Prime: 21773

Next Prime: 21787

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 5 ² × 13 × 67

Divisors: 1, 5, 13, 25, 65, 67, 325, 335, 871, 1675

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010100001111

Octal: 52417

Duodecimal: 10727

Hexadecimal: 550f

Square: 474150625

Square Root: 147.56354563373705

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

a(n) = 15n² + 3n + 1. A165806

Numbers k such that 100k+1, 100k+3, 100k+7, 100k+9 are all primes. A64687

a(n) = n*(n+1)*(8·n + 1)/6. A132124

-5-Knödel numbers. A225509

Main diagonal of Ludic array A255127 (and A255129): a(n) = A255127(n,n). A255410

a(n) is the smallest number that is the sum of both 2n-1 and 2n+1 consecutive primes. A213174

Absolute value of coefficient of x³ in polynomial whose zeros are 5 consecutive integers starting with the n-th integer. A127694

Numbers in A245385 where P, Q, R, and S are all distinct. A245386

a(n) = n*(n³ + 2·n² - 5·n + 10)/8. A294259

a(n) is least k such that k and 5k are anagrams in base n (written in base 10). A23097