1944
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
- 3
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 5460
- Proper Divisor Sum (Aliquot Sum)
- 3516
- 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
- 648
- Möbius Function
- 0
- Radical
- 6
- Omega Function (Ω)
- 8
- Little Omega Function (ω)
- 2
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
- 99
- 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
- yes
- Achilles Number
- yes
- Perfect Power
- no
- Smooth Number
- yes
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Generalized class numbers c_(n,1).at n=26A000233
- a(n) = a(n-1)*a(n-2).at n=5A000304
- a(n) is smallest number > a(n-1) of form a(i)*a(j), i < j < n.at n=31A000423
- a(n) is the solution to the postage stamp problem with n denominations and 4 stamps.at n=16A001214
- Index of (the image of) the modular group Gamma(n) in PSL_2(Z).at n=17A001766
- Number of partitions of floor(5n/2) into n nonnegative integers each no more than 5.at n=22A001975
- Prime numbers of measurement.at n=41A002049
- Bisection of A002470.at n=9A002286
- Order of largest (finite) group with n conjugacy classes.at n=12A002319
- Glaisher's function W(n).at n=19A002470
- a(1) = 1; for n>1, a(n) = a(n-1) + 1 + sum of distinct prime factors of a(n-1) that are < a(n-1).at n=53A003508
- 3-smooth numbers: numbers of the form 2^i*3^j with i, j >= 0.at n=46A003586
- Number of spanning trees with degrees 1 and 3 in S_4 X P_{2n-1}.at n=5A003756
- a(n) = 8*3^n.at n=5A005051
- a(n) = 10*n^3 - 6*n^2.at n=6A006592
- MU-numbers: next term is uniquely the product of 2 earlier terms.at n=18A007335
- Triple factorial numbers a(n) = n!!!, defined by a(n) = n*a(n-3), a(0) = a(1) = 1, a(2) = 2. Sometimes written n!3.at n=12A007661
- a(n) = (2*n+1)^2*n!.at n=4A007681
- Numbers k such that phi(k) divides k.at n=40A007694
- Number of matrix bundles of codimension n (Euler transform of A001156).at n=16A007864