Properties of the Number -7781

Seven Hundred Eighty-One

Basics

Value: -7782 → -7781 → -7780

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 31 × 251

Divisors: 1, 31, 251, 7781

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -1111001100101

Octal: -17145

Duodecimal: -4605

Hexadecimal: -1e65

Square: 60543961

Square Root: 88.20997676000147

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

Irregular triangle read by rows where T(n,k) is the number of integer compositions of n with k excedances (parts above the diagonal), all zeros removed. A352524

Number of integer partitions of n whose run-lengths are neither weakly increasing nor weakly decreasing. A332641

a(1) = 1; a(n) = max{ 5·a(k) + a(n-k) | 1 <= k <= n/2 } for n > 1. A130667

a(n) = n*(8·n+3). A139276

a(n) = 6ⁿ + n. A226200

Terms of A121707 not in A267999. A306097

Number of integer compositions of n with exactly one part above the diagonal. A351983

a(n) = A379597(n) - A381710(n). A381711

dot_product(n,n-1,...2,1)*(7,8,...,n,1,2,3,4,5,6). A26066

a(n) = 10000·log₁₀(n) rounded down. A4228