Properties of the Number 21215

Twenty-One Thousand Two Hundred Fifteen

Basics

Value: 21214 → 21215 → 21216

Parity: odd

Prime: No

Previous Prime: 21211

Next Prime: 21221

Digit Sum: 11

Digital Root: 2

Palindrome: No

Factorization: 5 × 4243

Divisors: 1, 5, 4243, 21215

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001011011111

Octal: 51337

Duodecimal: 1033B

Hexadecimal: 52df

Square: 450076225

Square Root: 145.653698888837

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 consecutive runs of 3 odd nonprimes congruent to 1 mod 4 below 10ⁿ. A93187

Sums of squared coefficients in the negative powers of the Catalan function: a(n) = ∑_k=1..n+1 [x^n-k+1] 1/C(x²)^k, where C(x) is the g.f. of A000108. A132459

Number of strings of numbers x(i=1..n) in 0..2 with sum i²*x(i)³ equal to n²*8. A184311

Numbers n such that 36n+11, 36(n+1)+11, 36(n+2)+11 and 36(n+3)+11 are prime. A255608

Multiplicity of highest weight (or singular) vectors associated with character chi₅₇ of Monster module. A34445

Number of down-up parking functions of length n. A264963

Decimal expansion of 1/211. A21215