Properties of the Number 19845

Nineteen Thousand Eight Hundred Forty-Five

Basics

Value: 19844 → 19845 → 19846

Parity: odd

Prime: No

Previous Prime: 19843

Next Prime: 19853

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ⁴ × 5 × 7 ²

Divisors: 1, 3, 5, 7, 9, 15, 21, 27, 35, 45

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100110110000101

Octal: 46605

Duodecimal: B599

Hexadecimal: 4d85

Square: 393824025

Square Root: 140.87228258248675

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

Triangle read by rows: a(n, m) = S1(n, m)*3^n-m, where S1 are the signed Stirling numbers of first kind A008275 (n >= 1, 1 <= m <= n). A51141

Numbers with exactly 3 distinct odd prime divisors {3,5,7}. A147576

Number of balanced set partitions of {1..n}. A340598

25-gonal numbers: a(n) = n*(23·n-21)/2. A255184

Number of noncommutative SL(2,C)-invariants of degree n in 5 variables. A7043

Triangular array read by rows: row n shows the coefficients of the polynomial p(x,n) constructed as in Comments; these polynomials form a strong divisibility sequence. A327321

Number of elements of GF(3ⁿ) with trace 0 and subtrace 0. A74000

T(n,k)=Number of (n+1)X(k+1) arrays of permutations of 0..(n+1)*(k+1)-1 with each element having index change +-(.,.) 0,0 0,2 or 2,1. A264195

Successive denominators of Wallis's approximation to π/2 (reduced). A1902

Denominators of the column sums of the BG2 matrix. A161736