Properties of the Number 9999

Nine Thousand Nine Hundred Ninety-Nine

Basics

Value: 9998 → 9999 → 10000

Parity: odd

Prime: No

Previous Prime: 9973

Next Prime: 10007

Digit Sum: 36

Digital Root: 9

Palindrome: Yes

Factorization: 3 ² × 11 × 101

Divisors: 1, 3, 9, 11, 33, 99, 101, 303, 909, 1111

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011100001111

Octal: 23417

Duodecimal: 5953

Hexadecimal: 270f

Square: 99980001

Square Root: 99.99499987499375

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) = 10ⁿ - 1. A2283

Repdigit numbers, or numbers whose digits are all equal. A10785

Smallest number whose sum of digits is n. A51885

Kaprekar numbers: positive numbers n such that n = q+r and n² = q·10^m+r, for some m >= 1, q >= 0 and 0 <= r < 10^m, with n ≠ 10^a, a >= 1. A6886

Trimorphic numbers: n³ ends with n. Also m-morphic numbers for all m > 5 such that m-1 is not divisible by 10 and m == 3 (mod 4). A33819

Denominators of greedy Egyptian fraction for e - 2. A6525

a(n)³ is smallest cube containing exactly n 9's. A48374

a(n) = n⁴ - 1. A123865

Largest number whose 4th power has n digits. A114322

The sequence S = a(1), a(2), ... is defined by a(1)=1, if d,e,f are consecutive digits then we do not have d >= e > f, and S is always extended with the smallest integer not yet present in S. A239215