Properties of the Number 39940

Thirty-Nine Thousand Nine Hundred Forty

Basics

Value: 39939 → 39940 → 39941

Parity: even

Prime: No

Previous Prime: 39937

Next Prime: 39953

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 2 ² × 5 × 1997

Divisors: 1, 2, 4, 5, 10, 20, 1997, 3994, 7988, 9985

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 1001110000000100

Octal: 116004

Duodecimal: 1B144

Hexadecimal: 9c04

Square: 1595203600

Square Root: 199.8499437077729

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

G.f.: q * ∏_m>=1 (1-q^m)⁸*(1-q^2m)⁸. A2288

Number of 5 X n (0,1) matrices such that each row and each column is nondecreasing or nonincreasing. A86115

Expansion of q * (φ(q) * ψ(-q))⁸ in powers of q where φ(), ψ() are Ramanujan θ functions. A216711

Expansion of e.g.f. sec(exp(x)*log(x+1)). A12279

Numbers k such that abs(prime(k)-k*τ(k)) < sqrt(k). A68543

Number of perfect matchings in the twisted graph (C₄ X C_n)_{(13)(24)}. A220868

Number of walks within N³ (the first octant of Z³) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (1, -1, 1), (1, 0, -1), (1, 1, 0)}. A149274

Smallest k for which k, 2k, ... nk all contain the digit 9. A39940

T(n,k)=Number of (n+2)X(k+2) binary arrays avoiding patterns 001 and 110 in rows and columns. A202052