Properties of the Number 19990

Nineteen Thousand Nine Hundred Ninety

Basics

Value: 19989 → 19990 → 19991

Parity: even

Prime: No

Previous Prime: 19979

Next Prime: 19991

Digit Sum: 28

Digital Root: 1

Palindrome: No

Factorization: 2 × 5 × 1999

Divisors: 1, 2, 5, 10, 1999, 3998, 9995, 19990

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100111000010110

Octal: 47026

Duodecimal: B69A

Hexadecimal: 4e16

Square: 399600100

Square Root: 141.3859964777276

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,k)=Number of length n+2 0..k arrays with the sum of medians of adjacent triples multiplied by some arrangement of +-1 equal to zero. A253129

Number of integer partitions of n - 1 containing fewer 1's than any other part. A364159

Indices of primes in the tetranacci sequence A000288. A247561

Number of partitions p of n such that (maximal multiplicity of the parts of p) > (maximal part of p). A240314

Number of inequivalent ways to cut an n X n square into squares with integer sides, such that the dissection has one reflective symmetry in an axis parallel to a side, but no other symmetries. A240125

a(1)=1, a(n) = a(n-1) + n³ if n odd, a(n) = a(n-1) + n¹ if n is even. A140153

Numbers k such that k and k² use only the digits 0, 1, 3, 6 and 9. A136850

2*(10ⁿ-5), n>0. A173813

Expansion of -16/(sqrt(12·x+2·sqrt(1-4·x)+2)-sqrt(1-4·x)-1)²+1/x²-1. A239425

Number of length n+2 0..5 arrays with the sum of medians of adjacent triples multiplied by some arrangement of +-1 equal to zero. A253126