Properties of the Number 21185

Twenty-One Thousand One Hundred Eighty-Five

Basics

Value: 21184 → 21185 → 21186

Parity: odd

Prime: No

Previous Prime: 21179

Next Prime: 21187

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 5 × 19 × 223

Divisors: 1, 5, 19, 95, 223, 1115, 4237, 21185

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001011000001

Octal: 51301

Duodecimal: 10315

Hexadecimal: 52c1

Square: 448804225

Square Root: 145.5506784594287

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 nXk 0..1 arrays with each 1 horizontally or vertically adjacent to 1 or 3 1s. A295097

Number of binary strings of length n with no substrings equal to 000, 010, or 111. A164317

Numbers such that the sum of the factorials of the digits of the fourth power is a square. A126077

Records in A096335 (values). A221181

Number of n X 2 0..1 arrays with every element equal to 1, 3, 4 or 6 king-move adjacent elements, with upper left element zero. A298057

Number of nX5 0..1 arrays with each 1 horizontally or vertically adjacent to 1 or 3 1s. A295094

Number of ternary length-2 squarefree words of length n not containing the subwords 021 or 10. A373554

Number of walks within N³ (the first octant of Z³) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 1, -1), (0, 0, 1), (1, 0, 0)}. A149812

Number of n X n 0..1 arrays with each 1 horizontally or vertically adjacent to 1 or 3 1's. A295090

Decimal expansion of 1/181. A21185