1548
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
- 18
- Divisor Sum
- 4004
- Proper Divisor Sum (Aliquot Sum)
- 2456
- 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
- 504
- Möbius Function
- 0
- Radical
- 258
- Omega Function (Ω)
- 5
- 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
- 122
- 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
- Numbers of the form (p^2 - 1)/120 where p is 1 or prime.at n=39A002381
- Self numbers divisible by sum of their digits (or, self numbers which are also Harshad numbers).at n=37A003219
- Record values in A005210.at n=43A005211
- Alkane (or paraffin) numbers l(7,n).at n=14A005994
- Coordination sequence T3 for Zeolite Code STI.at n=27A008236
- Numbers k such that k | 8^k + 8.at n=16A015897
- Number of lines through exactly 5 points of an n X n grid of points.at n=26A018812
- Number of lines through exactly 5 points of an n X n grid of points.at n=28A018812
- Number of lines through exactly 6 points of an n X n grid of points.at n=33A018813
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite MTW = ZSM-12 Nan[AlnSi28-nO56] starting with a T7 atom.at n=10A019193
- a(n) = Sum_{k=1..n} k*[ (n/k)*[ n/k ] ].at n=21A024932
- a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-3)*a(3) for n >= 4, with initial terms 0, 1, 1, 0.at n=19A025250
- Partial sums of A028357.at n=34A028358
- a(n) = n*(n+7).at n=36A028563
- Expansion of (theta_3(z)*theta_3(19z) + theta_2(z)*theta_2(19z))^3.at n=32A028643
- Numbers whose sum of divisors is palindromic.at n=50A028980
- Numbers with 18 divisors.at n=25A030636
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 18.at n=34A031516
- Every run of digits of n in base 11 has length 2.at n=17A033009
- Numbers whose base-6 expansion has no run of digits with length < 2.at n=41A033019