Properties of the Number 21860

Twenty-One Thousand Eight Hundred Sixty

Basics

Value: 21859 → 21860 → 21861

Parity: even

Prime: No

Previous Prime: 21859

Next Prime: 21863

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 2 ² × 5 × 1093

Divisors: 1, 2, 4, 5, 10, 20, 1093, 2186, 4372, 5465

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010101100100

Octal: 52544

Duodecimal: 10798

Hexadecimal: 5564

Square: 477859600

Square Root: 147.85127662620977

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

T(n,k)=Number of length n+k 0..3 arrays with at most one downstep in every k consecutive neighbor pairs. A258730

Numbers m > 0 that have a divisor d > 1 with binomial(m+d, d) == 1 mod m. A290040

Numbers k such that the ring of integers of Q(2^1/k) is not Z[2^1/k]. A342390

a(n) = ∑_k=1..n floor(n/(2·k-1))^k. A350147

Decimal part of n-th root of a(n) starts with digit 8. A34085

n+A001045(n+1). A81660

Numbers that are not the difference of two binary palindromes (A006995). A290393

a(n) = ∑_k=0..2n (k+1) * A027113(n, 2n-k). A27138

Number of length n+5 0..3 arrays with at most one downstep in every 5 consecutive neighbor pairs. A258727

Number of length n+4 0..3 arrays with at most one downstep in every n consecutive neighbor pairs. A258734