Properties of the Number 39865

Thirty-Nine Thousand Eight Hundred Sixty-Five

Basics

Value: 39864 → 39865 → 39866

Parity: odd

Prime: No

Previous Prime: 39863

Next Prime: 39869

Digit Sum: 31

Digital Root: 4

Palindrome: No

Factorization: 5 × 7 × 17 × 67

Divisors: 1, 5, 7, 17, 35, 67, 85, 119, 335, 469

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1001101110111001

Octal: 115671

Duodecimal: 1B0A1

Hexadecimal: 9bb9

Square: 1589218225

Square Root: 199.66221475281696

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

Narayana's cows sequence: a(0) = a(1) = a(2) = 1; thereafter a(n) = a(n-1) + a(n-3). A930

Octagonal pyramidal numbers: a(n) = n*(n+1)*(2·n-1)/2. A2414

a(n) = a(n-1) + a(n-3) for n >= 3, with a(0) = 1, a(1) = a(2) = 0. This recurrence can also be used to define a(n) for n < 0. A78012

Expansion of (1-x)³/(1 - 4·x + 3·x² - x³). A52529

Expansion of (1 - x)/(1 + x - 2·x² + x³). A78039

a(n) = n-1, if n <= 2, otherwise A107458(n-1) + A107458(n-2). A135851

Number of ways to tile a 2 X n room with 1 X 2 Tatami mats. At most 3 Tatami mats may meet at a point. A68921

a(0) = 0, a(1) = 1, a(2) = 2; for n > 2, a(n) = a(n-1) + 2·a(n-2) + a(n-3). A141015

T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with no 2X2 subblock having its minimum diagonal element less than its minimum antidiagonal element. A251100

Least positive integer m with π(m·n) = φ(m+n), where π(.) is the prime-counting function and φ(.) is Euler's totient function. A247602