Properties of the Number 1998

One Thousand Nine Hundred Ninety-Eight

Basics

Value: 1997 → 1998 → 1999

Parity: even

Prime: No

Previous Prime: 1997

Next Prime: 1999

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 2 × 3 ³ × 37

Divisors: 1, 2, 3, 6, 9, 18, 27, 37, 54, 74

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 11111001110

Octal: 3716

Duodecimal: 11A6

Hexadecimal: 7ce

Square: 3992004

Square Root: 44.69899327725402

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

Signature-permutation of a Catalan automorphism: Reflect a rooted plane binary tree; Deutsch's 1998 involution on Dyck paths. A57163

Triangular matchstick numbers: a(n) = 3·n*(n+1)/2. A45943

Number of conjugacy classes in GL(n,2). A6951

Number of distinct products i·j*k with 1 <= i < j < k <= n. A27430

Triangle R, read by rows, such that R³ transforms column k of R³ into column k+1 of R³, so that column k of R³ equals column 0 of R^3·k+3, where R³ denotes the matrix cube of R. A113389

Number of maximal Golomb rulers of length n. A325683

Number of strict integer partitions of n containing some three possibly equal parts (a,b,c) such that a + b = c. A variation of sum-full strict partitions. A363226

Numbers whose multiset of prime factors is separable but has no alternating permutation. A345173

Number of ways to split an integer partition of n into consecutive subsequences with equal sums. A317715

a(n) = 1 + ∑_i=1..n (n-i+1)*φ(i). A5598

We use cookies

Some cookies are essential for Natory to function, like keeping you signed in. We also use optional cookies to understand how the app is used and improve it over time. Learn more in our Privacy Policy. You can manage your preferences anytime.