Properties of the Number 81000

Eighty-One Thousand

Basics

Value: 80999 → 81000 → 81001

Parity: even

Prime: No

Previous Prime: 80989

Next Prime: 81001

Digit Sum: 9

Digital Root: 9

Palindrome: No

Factorization: 2 ³ × 3 ⁴ × 5 ³

Divisors: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110001101000

Octal: 236150

Duodecimal: 3AA60

Hexadecimal: 13c68

Square: 6561000000

Square Root: 284.60498941515414

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: Yes

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

Triangle read by rows: coefficients T(n,k) of a binomial decomposition of nⁿ as Sum(k=0..n)T(n,k)*binomial(n,k). A244120

Numbers of form 3ⁱ*10^j, with i, j >= 0. A25616

Numbers of form 9ⁱ*10^j, with i, j >= 0. A25635

a(n) = 3·n³. A117642

Heinz numbers of Look-and-Say partitions without distinct multiplicities (non Wilf). A384006

a(n) = floor(n/5)*floor((n+1)/5)*floor((n+2)/5)*floor((n+3)/5)*floor((n+4)/5). A8382

Coefficients in q-expansion of (6·E₂²*E₄ - 8·E₂*E₆ + 3·E₄² - E₂⁴)/6912, where E₂, E₄, E₆ are the Eisenstein series shown in A006352, A004009, A013973, respectively. A282211

Numbers z such that there is a solution to x³ + y⁴ = z⁵ with x, y, z >= 1. A300565

Triangle read by rows: T(n,k) is the number of labeled commutative monoids of order n with k idempotents. A58159

a(n) = ∏_{d∣n, d<n} A260443(d). A293216