Properties of the Number 19440

Nineteen Thousand Four Hundred Forty

Basics

Value: 19439 → 19440 → 19441

Parity: even

Prime: No

Previous Prime: 19433

Next Prime: 19441

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 ⁴ × 3 ⁵ × 5

Divisors: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 100101111110000

Octal: 45760

Duodecimal: B300

Hexadecimal: 4bf0

Square: 377913600

Square Root: 139.427400463467

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: Yes

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

Numbers with an even number of prime factors (counted with multiplicity) that can be factored into squarefree semiprimes (A320911) but cannot be factored into distinct semiprimes (A320892). A320893

Numbers k such that ∑_j p_j = ∑_j e_j where ∏_j p_j^e_j is the prime factorization of k. A54411

6th binomial transform of (0,0,1,0,0,0, ...). A81136

Triangle read by rows: T(n,k) is the number of partitions of an n-set having k singleton blocks (0<=k<=n). A124323

a(n) = n^n-2 * binomial(n,2). A81131

Numbers which can be expressed as the product of a number and its reversal in at least two different ways. A66531

Completely multiplicative function with a(prime(k)) = prime(k)*prime(k+1). A191002

Number of product-free subsets of {1..n}. A326489

Triangle whose (i,j)-th entry is binomial(i,j)*6^i-j. A38255

Triangle read by rows, Xⁿ * [1,0,0,0,...]; where X = a tridiagonal matrix with (1,2,3,...) in the main diagonal and (1,1,1,...) in the sub and subsubdiagonals. A140735