Properties of the Number 21866

Twenty-One Thousand Eight Hundred Sixty-Six

Basics

Value: 21865 → 21866 → 21867

Parity: even

Prime: No

Previous Prime: 21863

Next Prime: 21871

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 2 × 13 × 29 ²

Divisors: 1, 2, 13, 26, 29, 58, 377, 754, 841, 1682

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010101101010

Octal: 52552

Duodecimal: 107A2

Hexadecimal: 556a

Square: 478121956

Square Root: 147.87156589419075

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

Number of integer partitions of n such that every set of distinct parts has a different sum. A325862

a(n) = 26·n². A244633

Expansion of ∏_k=1..12 theta₃(q^k), where theta₃() is the Jacobi θ function. A320246

Given the infinite continued fraction (1+i)+((1+i)/(1+i)+((1+i)/((1+i)+...)))), where i is the square root of (-1), this is the denominator of the convergents. A93727

Number of step shifted (decimated) sequence structures using exactly three different symbols. A56397

Nodes of tree generated as follows: (1,2) is an edge, and if (x,y) is an edge, then (y,x·y) and (y,x² + y²) are edges. A228939

Number of 4 X n 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero. A302152

Numbers whose base-2 representation has exactly 14 runs. A43581

Number of primitive (aperiodic) step shifted (decimated) sequence structures using exactly three different symbols. A56407

Number of 2-anisohedral polyominoes of order n. A120646