13424
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 10
- Divisor Sum
- 26040
- Proper Divisor Sum (Aliquot Sum)
- 12616
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6704
- Möbius Function
- 0
- Radical
- 1678
- Omega Function (Ω)
- 5
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 89
- 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) = 10000*log_10(n) rounded down.at n=21A004228
- a(n) = 10000*log_10(n) rounded to the nearest integer.at n=21A004229
- Rhombi (in 3 different orientations) in a rhombus with 60-degree acute angles.at n=31A052153
- Numerator of b(n) = Sum_{k'<=n} 1/k', where k' denotes the squarefree numbers.at n=13A072980
- Triangle read by rows: the numbers B_2(n,k) from the Harju and Nowotka paper.at n=49A102416
- Combinatorial triangle !n. This table read by rows gives the coefficients of general sum formulas of n-th left factorials (A003422). The k-th row (k>=1) contains T(i,k) for i=1 to 2*k and k=1 to n-2, where T(i,k) satisfies !n = n + Sum_{k=1..n-2} Sum_{i=1..2*k} T(i,k) * C(n-k-1,i).at n=31A102639
- Leading column of A102416.at n=13A102864
- A logarithmic transform of the Fibonacci numbers A000045.at n=7A112006
- a(n) = 839*n.at n=16A135639
- Number of lines through at least 2 points of a 9 X n grid of points.at n=27A160849
- Numbers equal to the arithmetic derivative of their Euler totient function.at n=33A248815
- 29-gonal numbers: a(n) = n*(27*n-25)/2.at n=32A255187
- Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000101 00010101 or 01010101.at n=9A260008
- Numbers k such that (86*10^k - 77)/9 is prime.at n=24A273783
- a(n) = a(n-2) + a(n-3) + a(n-4) with a(0) = 0, a(1) = a(2) = 1, a(3) = 0.at n=28A277252
- Numbers k such that (26*10^k - 173)/3 is prime.at n=18A293910
- Partial sums of A299898.at n=29A299899
- Expansion of Product_{k>=1} 1/(1 - x^k)^(p(k)-p(k-1)), where p(k) = number of partitions of k (A000041).at n=23A304967
- Number of integer partitions of n whose length and maximum both divide n.at n=63A326843
- a(n) is the numerator of the sum of the reciprocals of the first n squarefree numbers.at n=9A354417