Properties of the Number 19021

Nineteen Thousand Twenty-One

Basics

Value: 19020 → 19021 → 19022

Parity: odd

Prime: No

Previous Prime: 19013

Next Prime: 19031

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 23 × 827

Divisors: 1, 23, 827, 19021

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100101001001101

Octal: 45115

Duodecimal: B011

Hexadecimal: 4a4d

Square: 361798441

Square Root: 137.91664149043072

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) = ∑_k=1..n k*φ(k). A11755

Numbers k such that 3·k! - 1 is prime. A76134

a(0)=2, a(n) = n²+a(n-1). A153056

a(n) = A056520(n)+1 for n>0, a(0)=1. A179904

Sieve performed by successive iterations of steps where step m is: keep m terms, remove the next 2 and repeat; as m = 1,2,3,.. the remaining terms form this sequence. A112560

Sieve performed by successive iterations of steps where step m is: keep m terms, remove the next 4 and repeat; as m = 1,2,3,.. the remaining terms form this sequence. A112562

a(n) is number of strings of length n that can be obtained by starting with abc and repeatedly doubling any substring in place and then discarding any string that contains two successive equal letters. A135017

a(n) = 36·n² - n. A157286

a(n) = 529·n² - 23. A158633

G.f. A(x) satisfies: A(x) = 1 + x·A(x/(1 - 6·x)) / (1 - 6·x)². A351812