Properties of the Number 20139

Twenty Thousand One Hundred Thirty-Nine

Basics

Value: 20138 → 20139 → 20140

Parity: odd

Prime: No

Previous Prime: 20129

Next Prime: 20143

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 7 ² × 137

Divisors: 1, 3, 7, 21, 49, 137, 147, 411, 959, 2877

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100111010101011

Octal: 47253

Duodecimal: B7A3

Hexadecimal: 4eab

Square: 405579321

Square Root: 141.91194452899305

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

Triangle T(n,k), n>=0, 0<=k<=n, read by rows: T(n,k) = number of simple graphs on n labeled nodes with k edges where each maximally connected subgraph has at most one cycle. A144228

Numbers n such that n⁶ + 272 is prime. A161998

Partial sums of A007694. A174030

First row of spectral array W(sqrt(3)). A22159

Triangle of coefficients in g.f. A(x,y) which satisfies: A(x,y) = ∑_n>=0 xⁿ/(1 - x·y*A(x,y)ⁿ). A340910

Number of integers in n-th generation of tree T(-2/3) defined in Comments. A274150

a(1) = a(3) = 0, and otherwise a(n) is the least multiple of prime(n) whose decimal representation ends with that of prime(n+1). A333845

Numbers k such that k·Lucas(k) + 1 is prime. A134696

Array A read by upward antidiagonals in which the entry in row n and column k is defined by A(n,k) = (1 + 2ⁿ*(6·k-3+2*(-1)ⁿ))/3, n,k >= 1. A257499

Pseudoprimes to base 11. A20139