Properties of the Number 87381

Eighty-Seven Thousand Three Hundred Eighty-One

Basics

Value: 87380 → 87381 → 87382

Parity: odd

Prime: No

Previous Prime: 87359

Next Prime: 87383

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 7 × 19 × 73

Divisors: 1, 3, 7, 9, 19, 21, 57, 63, 73, 133

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

5184 Try Today's Challenge

Representations

Binary: 10101010101010101

Octal: 252525

Duodecimal: 42699

Hexadecimal: 15555

Square: 7635439161

Square Root: 295.60277400592844

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

Jacobsthal sequence (or Jacobsthal numbers): a(n) = a(n-1) + 2·a(n-2), with a(0) = 0, a(1) = 1; also a(n) = nearest integer to 2ⁿ/3. A1045

a(2n) = 2·a(2n-1), a(2n+1) = 2·a(2n)+1 (also a(n) is the n-th number without consecutive equal binary digits). A975

a(n) = (4ⁿ - 1)/3. A2450

a(n) = C(n,2) + C(n,5) + ... + C(n, 3·floor(n/3)+2). A24495

Expansion of 1/((1-x)*(1+2·x)). A77925

Dispersion of A016813 (4k+1, k>1), by antidiagonals. A191667

a(n) is the index of F(n+1) at the unique occurrence of the ordered pair of reversed consecutive terms (F(n+1),F(n)) in Stern's diatomic sequence A002487, where F(k) denotes the k-th term of the Fibonacci sequence A000045. A86893

Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m·k + 1)*T(n-1, k, m) - m·k*(n-k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1 and m = 3, read by rows. A157154

An array A of the positive odd numbers, read by antidiagonals upwards, giving the present triangle T. A347834

A024494 prefixed by a 0. A131708