1782
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 4356
- Proper Divisor Sum (Aliquot Sum)
- 2574
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 540
- Möbius Function
- 0
- Radical
- 66
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 47
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Heptagonal numbers (or 7-gonal numbers): n*(5*n-3)/2.at n=27A000566
- Expansion of (theta_3(z)*theta_3(7z)+theta_2(z)*theta_2(7z))^3.at n=16A002653
- Number of connected Eulerian graphs with n unlabeled nodes.at n=8A003049
- Numbers that are the sum of 11 positive 6th powers.at n=28A003367
- Number of alternating sign n X n matrices symmetric with respect to both diagonals.at n=8A005162
- Number of n-bead bracelets (turnover necklaces) of two colors with 6 red beads and n-6 black beads.at n=16A005513
- Coefficients of Chebyshev polynomials.at n=8A005583
- a(n) = 2*a(n-1) + a(n-2) - a(n-3) for n >= 3, starting with a(0) = 1, a(1) = 3, and a(2) = 6.at n=9A006356
- a(n) = Sum_{k=1..n-1} k XOR n-k.at n=49A006582
- Percolation series for hexagonal lattice.at n=16A006803
- Inverse Moebius transform applied twice to squares.at n=29A007433
- Coordination sequence T7 for Zeolite Code MFS.at n=26A008179
- Year of birth of n-th President of U.S.A.at n=7A008745
- Number of squarefree palindromes over {0, 1, 2} of length 2n+1.at n=25A012212
- Even heptagonal numbers (A000566).at n=13A014640
- Numbers k such that k | (phi(k) * sigma(k)) but (phi(k) + sigma(k))/k does not increase.at n=20A015708
- Bachet's equation: X^2 + k = Y^3, k=999. The terms are values of X, corresponding Y are in A248481.at n=3A016107
- Powers of fifth root of 2 rounded down.at n=54A018117
- Powers of fifth root of 4 rounded down.at n=27A018123
- Powers of fifth root of 8 rounded down.at n=18A018135