15392
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 33516
- Proper Divisor Sum (Aliquot Sum)
- 18124
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6912
- Möbius Function
- 0
- Radical
- 962
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 53
- 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
- a(n) = (d(n)-r(n))/2, where d = A026046 and r is the periodic sequence with fundamental period (0,1,0,1).at n=41A026047
- 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 61.at n=38A031559
- Base 9 digits are, in order, the first n terms of the periodic sequence with initial period 2,3,1,0.at n=4A037756
- a(n) = ((8^n) - (-6)^n)/14.at n=6A053455
- Number of collinear triples in a 3 X n rectangular grid.at n=32A057566
- a(n) = 2*a(n-1) + 48*a(n-2), a(0)=0, a(1)=1.at n=6A080921
- Least positive k such that k * [RSA-640]^n - 1 is prime, where RSA-640 is the 193 decimal digit RSA challenge number A391940(14).at n=34A108573
- Product of a(n-2) and digit reversal of a(n-1).at n=7A109213
- Row sums of correlation triangle for (1+x)^3/(1-x).at n=32A115293
- Triangle read by rows: numbers of isomers of unbranched a-4-catapolyheptagons.at n=46A120653
- Numbers of isomers of unbranched a-4-catapolyheptagons - see Brunvoll reference for precise definition.at n=8A121138
- E.g.f. A(x) = Sum_{n>=0} exp(3^n*x)*x^n/n!.at n=5A135079
- Fourth entry in row n of triangle in A169945.at n=18A169948
- Number of partitions p of n such that if h = min(p), then h is an (h,1)-separator of p; see Comments.at n=52A239497
- Fixed points of f(n) = A252753(n-1).at n=44A253789
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 437", based on the 5-celled von Neumann neighborhood.at n=6A272154
- a(n) is the smallest number which has a water-capacity of n.at n=18A275339
- The least common multiple of 1+n and 1+n^2.at n=31A281660
- Numbers that are the sum of fourth powers of three distinct positive integers in arithmetic progression.at n=18A306214
- a(n) = n*(2*(n - 2)*n + (-1)^n + 3)/4.at n=32A323724