Properties of the Number 31878

Thirty-One Thousand Eight Hundred Seventy-Eight

Basics

Value: 31877 → 31878 → 31879

Parity: even

Prime: No

Previous Prime: 31873

Next Prime: 31883

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 2 × 3 ² × 7 × 11 × 23

Divisors: 1, 2, 3, 6, 7, 9, 11, 14, 18, 21

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111110010000110

Octal: 76206

Duodecimal: 16546

Hexadecimal: 7c86

Square: 1016206884

Square Root: 178.54411219639812

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

Tritriangular numbers: a(n) = binomial(binomial(n,2),2) = n*(n+1)*(n-1)*(n-2)/8. A50534

G.f. satisfies A(x) = 1 + x*(1 + 1/A(x)³). A364407

Triangular numbers which are products of triangular numbers larger than 1. A68143

a(n) is the number of Dyck paths of semilength n+6 having its first peak at height n+1. A5557

Expansion of θ series of {E₇}* lattice in powers of q^1/2. A3781

Numbers k such that ω(k) = 5 and the largest prime factor of k equals the sum of its remaining distinct prime factors, where ω(k) = A001221(k). A383729

T(n,k)=Number of nXk 0..1 arrays with every element unequal to 0, 2, 3, 4, 6, 7 or 8 king-move adjacent elements, with upper left element zero. A317271

Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,0) = 0ⁿ and T(n,k) = k * ∑_r=0..n binomial(n,r) * binomial(n+3·r+k,n)/(n+3·r+k) for k > 0. A378237

Expansion of θ series of E₇ lattice in powers of q². A4008

Triangular numbers that are the product of 2 palindromes greater than 1. A115744