1872
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
- 30
- Divisor Sum
- 5642
- Proper Divisor Sum (Aliquot Sum)
- 3770
- 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
- 576
- Möbius Function
- 0
- Radical
- 78
- Omega Function (Ω)
- 7
- 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
- 24
- Smith Number
- yes
- 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
- Expansion of e.g.f. sin(sin(x)) (odd powers only).at n=4A003712
- Number of partitions of n-set into odd blocks.at n=9A003724
- Theta series of D_4 lattice; Fourier coefficients of Eisenstein series E_{gamma,2}.at n=45A004011
- Expansion of (1+x^2) / ( (1-x)^2 * (1-x^3)^2 ).at n=34A006501
- Coordination sequence T1 for Zeolite Code AFG.at n=30A008012
- Coordination sequence T3 for Zeolite Code LTN.at n=30A008142
- a(n) = floor(n/4)*floor((n+1)/4)*floor((n+2)/4).at n=50A008218
- Year of birth of n-th President of U.S.A.at n=29A008745
- Aliquot sequence starting at 276.at n=4A008892
- Expansion of e.g.f. cosh(sinh(x))/exp(x).at n=8A009152
- "Pascal sweep" for k=7: draw a horizontal line through the 1 at C(k,0) in Pascal's triangle; rotate this line and record the sum of the numbers on it (excluding the initial 1).at n=35A009504
- a(n) = n^2*(n+1).at n=12A011379
- Numbers k such that the periodic part of the continued fraction for sqrt(k) contains a single 1.at n=50A013648
- a(n) = (2*n - 11)*n^2.at n=12A015245
- Numbers k such that k | (phi(k) * sigma(k)) but (phi(k) + sigma(k))/k does not increase.at n=22A015708
- Coordination sequence T1 for Zeolite Code TER.at n=29A016433
- Expansion of 1/(1-x^7-x^8-x^9-x^10-x^11-x^12-x^13-x^14-x^15).at n=46A017864
- Binomial transform of Thue-Morse sequence A010060.at n=12A019302
- a(n) is the concatenation of n and 4n.at n=17A019552
- Pisot sequence T(3,5).at n=16A020745