Properties of the Number 20385

Twenty Thousand Three Hundred Eighty-Five

Basics

Value: 20384 → 20385 → 20386

Parity: odd

Prime: No

Previous Prime: 20369

Next Prime: 20389

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ³ × 5 × 151

Divisors: 1, 3, 5, 9, 15, 27, 45, 135, 151, 453

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100111110100001

Octal: 47641

Duodecimal: B969

Hexadecimal: 4fa1

Square: 415548225

Square Root: 142.7760484114895

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

Diagonal in array of n-gonal numbers A081422. A81437

Numbers n such that sopf(n) = sopf(n-1) + sopf(n-2), where sopf(x) = sum of the distinct prime factors of x. A75565

Expansion of (1 - x³ - x⁴)/((1 - x³ - x⁴)² - 4·x⁷). A376730

This table shows the coefficients of combinatorial formulas needed for generating the sequential sums of p-th powers of binomial coefficients C(n,6). The p-th row (p>=1) contains a(i,p) for i=1 to 6·p-5, where a(i,p) satisfies ∑_i=1..n C(i+5,6)^p = 7·C(n+6,7) * ∑_i=1..6·p-5 a(i,p) * C(n-1,i-1)/(i+6). A87110

Triangle read by rows: T(0,0)=1; for n >= 1 T(n,k) is the coefficient of x^k in the monic characteristic polynomial of the tridiagonal n X n matrix with main diagonal 5,5,5,... and sub- and superdiagonals 1,1,1,... (0 <= k <= n). A123967

Triangle of coefficients of Chebyshev's S(n,x+5) polynomials (exponents of·in increasing order). A207824

Number of pairs with two different elements which can be obtained by selecting unique elements from two sets with n+1 and n² elements respectively and n common elements. A85490

Numbers n such that p = n² + 2, p+2 and p+6 are consecutive primes. A86380

Sums of groups in A075639. A75640

a(n) = 26·n² + 1. A158549