Properties of the Number 999

Nine Hundred Ninety-Nine

Basics

Value: 998 → 999 → 1000

Parity: odd

Prime: No

Previous Prime: 997

Next Prime: 1009

Digit Sum: 27

Digital Root: 9

Palindrome: Yes

Factorization: 3 ³ × 37

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

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

8509 Try Today's Challenge

Representations

Binary: 1111100111

Octal: 1747

Duodecimal: 6B3

Hexadecimal: 3e7

Square: 998001

Square Root: 31.606961258558215

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

Numbers k such that (68·10^k + 7)/3 is prime. A270613

a(n) = 10ⁿ - 1. A2283

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

Sub-perfect powers: perfect powers (squares, cubes etc., not including 1) minus 1. A45542

Smallest number whose sum of digits is n. A51885

Number of integer partitions of n of which every permutation has a consecutive monotone triple, i.e., a triple (..., x, y, z, ...) such that either x <= y <= z or x >= y >= z. A344654

Number of integer partitions of n without an alternating permutation. A345165

Product of the cube of a prime (A030078) and a different prime. A65036

Numbers that are palindromic in bases 10 and 14. A29969

a(n) = n³ - 1. A68601