Properties of the Number 21385

Twenty-One Thousand Three Hundred Eighty-Five

Basics

Value: 21384 → 21385 → 21386

Parity: odd

Prime: No

Previous Prime: 21383

Next Prime: 21391

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 5 × 7 × 13 × 47

Divisors: 1, 5, 7, 13, 35, 47, 65, 91, 235, 329

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001110001001

Octal: 51611

Duodecimal: 10461

Hexadecimal: 5389

Square: 457318225

Square Root: 146.23611045155707

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

RMS numbers: numbers n such that root mean square of divisors of n is an integer. A140480

Coefficients for step-by-step integration. A2398

Triangle read by rows: coefficients for predictor y(x₁) for step-by-step integration. A260780

a(n) = 4·n³ - 6·n² + 1. A141530

Odd elements to the right of the central elements of the 5-Pascal triangle A028313. A28325

Sum of prime divisors of n (with repetition) is one less than the sum of prime divisors (with repetition) of n+1. A228126

Numbers whose sum of the squares of divisors is also a square number. A46655

Regular triangle read by rows where T(n,k) is the number of labeled simple graphs on n vertices where all non-isolated vertices have degree k. A319729

Distinct odd elements in the 5-Pascal triangle A028313. A28319

a(n) = (n+3)²*n/2 + 1. A154560