Properties of the Number 40005

Forty Thousand Five

Basics

Value: 40004 → 40005 → 40006

Parity: odd

Prime: No

Previous Prime: 39989

Next Prime: 40009

Digit Sum: 9

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 5 × 7 × 127

Divisors: 1, 3, 5, 7, 9, 15, 21, 35, 45, 63

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 1001110001000101

Octal: 116105

Duodecimal: 1B199

Hexadecimal: 9c45

Square: 1600400025

Square Root: 200.0124996093994

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

Numbers m such that there are precisely 19 groups of order m. A298910

a(n) = floor(4ⁿ/((1+sqrt(5))/2)^2·n). A240523

a(n) = (3/4) * ∑_k>=0 (3·k)ⁿ/4^k. A255927

Multiples of 9 in which there is no common digit in successive terms. A83497

Numbers equal to the sum of their aliquot parts, each of them increased by 6. A304278

A(n, k) = A_n(k) where A_n(x) are the Eulerian polynomials, square array read by ascending antidiagonals, for n >= 0 and k >= 0. A326323

Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n) + 2·n, where a(0) = 1, a(1) = 2, b(0) = 3, b(1) = 4, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences. A294170

Number of nonempty labeled antichains of subsets of [n] such that the largest subset is of size 2. A379706

a(n) = 25·n² + 5. A158445

Triangle read by rows: T(n,k) is the number of nonempty labeled antichains of subsets of [n] such that the largest subset is of size k. A379712