Properties of the Number 19755

Nineteen Thousand Seven Hundred Fifty-Five

Basics

Value: 19754 → 19755 → 19756

Parity: odd

Prime: No

Previous Prime: 19753

Next Prime: 19759

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 5 × 439

Divisors: 1, 3, 5, 9, 15, 45, 439, 1317, 2195, 3951

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100110100101011

Octal: 46453

Duodecimal: B523

Hexadecimal: 4d2b

Square: 390260025

Square Root: 140.55248130146973

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

a(n) = ∑_d∣n φ(d)*3^n/d. A54610

Triangle T(n,k) = ∑_d∣n φ(d)*k^n/d. A54618

a(n) = ∑_d∣9 φ(d)*n^9/d. A54608

Take pairs (a, b), sorted on a, such that T(a)+T(b)=concatenation of a and b, where T(k) is the k-th triangular number A000217(k). Sequence gives values of a. A96031

a(n) is the smallest positive integer which can be represented as the sum of distinct nonzero icosahedral numbers in exactly n ways, or -1 if no such integer exists. A360215

L.g.f.: log(∑_k>=0 k! * x^{k*(k + 1}/2) / ∏_j=1..k (1 - x^j)). A331337

Square array, read by antidiagonals, where row n+1 equals the partial sums of the sequence resulting from removing the terms in the first column and main diagonal from row n, for n>=0, with row 0 consisting of all 1's. A130462

a(n) = floor(n*π/3). A274399

Decimal expansion of e/18. A19755

Table read by antidiagonals: T(n,k) (n >= 2, k >= 1) is the number of regions formed in a regular 2n-gon by straight line segments when connecting the k+1 points that divide each side into k equal parts to the equivalent point on the side diagonally opposite. A356799