Properties of the Number 7840

Seven Thousand Eight Hundred Forty

Basics

Value: 7839 → 7840 → 7841

Parity: even

Prime: No

Previous Prime: 7829

Next Prime: 7841

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 ⁵ × 5 × 7 ²

Divisors: 1, 2, 4, 5, 7, 8, 10, 14, 16, 20

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 1111010100000

Octal: 17240

Duodecimal: 4654

Hexadecimal: 1ea0

Square: 61465600

Square Root: 88.54377448471462

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

4-dimensional figurate numbers: a(n) = n·binomial(n+2, 3). A2417

Numbers k such that k divides 1 plus the sum of the first k primes. A128165

12-gonal (or dodecagonal) numbers: a(n) = n*(5·n-4). A51624

Numbers that are the sum of 3 positive 5th powers. A3348

a(n) = 10·n². A33583

Expansion of k/(4·q^1/2) in powers of q, where k defined by sqrt(k) = theta₂(0, q)/theta₃(0, q). A1938

Expansion of q^-1/2 * (η(q⁴) / η(q))⁴ in powers of q. A93160

Shortest edge c of (measured by the longest edge) primitive Euler bricks (a, b, c, sqrt(a² + b²), sqrt(b² + c²), sqrt(a² + c²) are integers). A31175

Triangle read by rows: the Bell transform of the triple factorial numbers A008544 without column 0. A4747

Expansion of (1-x)^-3 * (1-x²)^-2. A2624