Properties of the Number 42780

Forty-Two Thousand Seven Hundred Eighty

Basics

Value: 42779 → 42780 → 42781

Parity: even

Prime: No

Previous Prime: 42773

Next Prime: 42787

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 2 ² × 3 × 5 × 23 × 31

Divisors: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 1010011100011100

Octal: 123434

Duodecimal: 20910

Hexadecimal: a71c

Square: 1830128400

Square Root: 206.83326618317471

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) = n*(n + 1)*(n² - 3·n + 5)/6. A6484

Number of ways to partition the set of vertices of a convex {n+8}-gon into 3 non-intersecting polygons. A350116

Primitive terms of A388036. A388037

Maximal Laman number among all minimally rigid graphs on n vertices. A306420

a(1) = 1; for n >= 1, a(n+1) is smallest number such that the sums of any one, two or three of a(1), ..., a(n) are distinct (repetitions not allowed). A62065

a(n) = n*(n+1)*(7·n-6)/2. A256718

Triangle read by rows: T(n, k) = binomial(3·n, k-1) + binomial(3·n, n-k). A156003

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 491", based on the 5-celled von Neumann neighborhood. A272541

G.f.: 8th root of weight enumerator of [32,26,4] Reed-Muller code RM(3,5). A110842

Numerators of continued fraction convergents to sqrt(921). A42780