Properties of the Number 18915

Eighteen Thousand Nine Hundred Fifteen

Basics

Value: 18914 → 18915 → 18916

Parity: odd

Prime: No

Previous Prime: 18913

Next Prime: 18917

Digit Sum: 24

Digital Root: 6

Palindrome: No

Factorization: 3 × 5 × 13 × 97

Divisors: 1, 3, 5, 13, 15, 39, 65, 97, 195, 291

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100100111100011

Octal: 44743

Duodecimal: AB43

Hexadecimal: 49e3

Square: 357777225

Square Root: 137.5318145012273

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

T(n,m) = number of 0..m-1 integer arrays v[1..n] of length n with all autocorrelation values sum(i){v[i]*v[i-k]} distinct for k in 0..n-1. A171307

a(n) = d if the point (d,d) is shared by a record of different Dyck paths in the main diagonal of the diagram of the symmetries of σ described in A237593. A279286

Numbers that are repdigits with length > 2 in more than one base. A167783

T(n,k)=Number of nXk 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value 2-x(i,j). A230675

Numbers k such that k-4, k-2, k+2 and k+4 are prime. A173037

Numbers n such that there are precisely 5 groups of orders n and n + 1. A295991

Numbers m such that β(m) = τ(m)/2 + 1 where β(m) is the number of Brazilian representations of m and τ(m) is the number of divisors of m. A326381

Non-oblong composites m such that β(m) = τ(m)/2 + 1 where β(m) is the number of Brazilian representations of m and τ(m) is the number of divisors of m. A326388

Triangular numbers that can be written as sum of three positive cubes. A119977

a(1) = 9; a(n+1) = smallest triangular number > a(n) formed by adding at least one digit to a(n). A68624