Properties of the Number 21098

Twenty-One Thousand Ninety-Eight

Basics

Value: 21097 → 21098 → 21099

Parity: even

Prime: No

Previous Prime: 21089

Next Prime: 21101

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 2 × 7 × 11 × 137

Divisors: 1, 2, 7, 11, 14, 22, 77, 137, 154, 274

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001001101010

Octal: 51152

Duodecimal: 10262

Hexadecimal: 526a

Square: 445125604

Square Root: 145.25150601628886

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

Composite squarefree numbers n such that p+d(n) divides n+d(n), where p are the prime factors of n and d(n) the number of divisors of n. A228299

For n>0, a(n) is the least quasi-Carmichael number to base -n, extended to n=0 with the least composite squarefree integer. A29591

T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero. A298970

Number of primes between n⁵ and (n+1)⁵. A62517

a(n) = smallest k having at least four prime divisors d such that (d + n) | (k + n). A202159

Ordered product of the sides of primitive Pythagorean triangles divided by 60. A81752

Start with 0; then add one to each single digit. A158699

Even Quasi-Carmichael numbers. A262252

Smallest multiple of n with property that each digit is one less (mod 10) than the previous digit; or 0 if no such multiple exists. A62399

a(n) = 1 + (26·n+17+7·n²)*n/2. A95796