Properties of the Number 21199

Twenty-One Thousand One Hundred Ninety-Nine

Basics

Value: 21198 → 21199 → 21200

Parity: odd

Prime: No

Previous Prime: 21193

Next Prime: 21211

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 17 × 29 × 43

Divisors: 1, 17, 29, 43, 493, 731, 1247, 21199

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001011001111

Octal: 51317

Duodecimal: 10327

Hexadecimal: 52cf

Square: 449397601

Square Root: 145.59876373101525

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

Consider the mapping f(x/y) = (x+y)/(2xy) where x/y is a reduced fraction. Beginning with x₀ = 1 and y₀ = 2, repeated application of this mapping produces a sequence of fractions x_n/y_n; a(n) is the n-th numerator. A81475

Numerator of Hermite(n, 17/32). A160398

Numbers n such that φ(n) + π(n) = n+1. A233189

a(n) is the base-(-10) representation of a(n-1) read in base 10, starting from -1. A256639

Numbers k that are the maximum of integers |k3|, |k5|, |k7| with |k3| + |k5| + |k7| > 0, and |k3·sqrt(3) + k5·sqrt(5) + k7·sqrt(7)| is smaller than for any smaller value of k. A379918

Decimal expansion of 1/195. A21199