13989
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18656
- Proper Divisor Sum (Aliquot Sum)
- 4667
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9324
- Möbius Function
- 1
- Radical
- 13989
- Omega Function (Ω)
- 2
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 107
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Number of partitions of at most n into at most 5 parts.at n=38A002622
- Low temperature antiferromagnetic susceptibility for square lattice.at n=8A007215
- 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 78.at n=38A031576
- a(n)=floor{square((1*n^0+1*n^1+2*n^2+4*n^3)/(1*n^0+2*n^1+1*n^2))}.at n=30A086863
- Number of truncated ST-pairs O(q^n).at n=23A094866
- Integers k such that 10^k+49 is prime.at n=25A108054
- a(1) = a(2) = 1, a(n) = a(n-1) + A007947(a(n-2)) for n >= 3, i.e., a(n) = a(n-1) plus the largest squarefree divisor of a(n-2).at n=25A121367
- Column 3 of triangle A128545; a(n) is the coefficient of q^(3n+9) in the central q-binomial coefficient [2n+6,n+3].at n=10A128553
- a(n) = number of components of the graph P(n,2) (defined in Comments).at n=20A145667
- Shorthand for A157033, the smallest prime with 2^n digits.at n=13A157034
- a(n) = (19/28)*(3^n-1)*P(n-1)+(3/7)*(4*3^n-5)*P(n) where P() are the Pell numbers A000129.at n=4A187919
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 443", based on the 5-celled von Neumann neighborhood.at n=25A272227
- Strings of 5 digits from 1...9, such that no formula using the single digits in the given order exists that evaluates to 0.at n=16A288355
- Numbers k such that k!4 + 2^2 is prime, where k!4 = k!!!! is the quadruple factorial number (A007662).at n=34A291122
- Number of faces in the n-polygon diagonal intersection graph.at n=22A301748
- Sum of the fourth largest parts of the partitions of n into 10 parts.at n=40A326595
- Index where prime(n) appears as a term in A379442.at n=49A379558