Properties of the Number 8991

Eight Thousand Nine Hundred Ninety-One

Basics

Value: 8990 → 8991 → 8992

Parity: odd

Prime: No

Previous Prime: 8971

Next Prime: 8999

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ⁵ × 37

Divisors: 1, 3, 9, 27, 37, 81, 111, 243, 333, 999

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10001100011111

Octal: 21437

Duodecimal: 5253

Hexadecimal: 231f

Square: 80838081

Square Root: 94.82088377567464

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

Number of partitions of n in which no parts are multiples of 3. A726

Number of partitions of n into parts 3k and 3k+1 with at least one part of each type. A35618

Number of partitions of 4n into 4 parts. A238340

Numbers m such that m divides 10^m - 1. A14950

Total number of edges formed after n points have been placed in general position on each edge of a triangle (as in A365929). A366932

Numbers k such that k | 11^k + 1. A15960

Numbers whose square is the concatenation of two numbers k and k-2. A115442

T(n,k)=Number of 0..k arrays of length n with each element differing from at least one neighbor by something other than 1. A221573

a(n) = T(n,n-4), array T as in A055807. A55809

a(n) = 9*(10ⁿ - 1). A86580