11970
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 48
- Divisor Sum
- 37440
- Proper Divisor Sum (Aliquot Sum)
- 25470
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2592
- Möbius Function
- 0
- Radical
- 3990
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 5
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
- 94
- 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
- Expansion of g.f. 1/((1-2x)(1-3x)(1-5x)).at n=5A016273
- Theta series of A*_20 lattice.at n=34A023932
- T(2n,n+2), T given by A026769.at n=6A026884
- a(n) = 2*binomial(n,4).at n=21A034827
- Number of partitions of n with equal nonzero number of parts congruent to each of 0 and 4 (mod 5).at n=45A035565
- Triangle of coefficients arising in calculation of A002872 and A002874 (sorting numbers).at n=48A036073
- Triangle read by rows: T(n,k)=A(n,k)*binomial(n+k-1,n), where A(n,k) are the Eulerian numbers (A008292).at n=19A038675
- Denominators of row 4 of table described in A051714/A051715.at n=16A051723
- Number of bracelets of length n using exactly six different colored beads.at n=7A056346
- Number of primitive (period n) bracelets using exactly six different colored beads.at n=7A056352
- a(n) = a*b = x*y with (a-b) = (x+y) = A020882(n) (a>b, a>0, b>0, x>0, y>0), gcd(a, b) = gcd(x, y) = 1.at n=35A057229
- Numbers k such that sigma(x) = k has exactly 9 solutions.at n=29A060665
- Numbers k such that k + the reversal of k is a square.at n=42A061230
- Numbers k such that (1/k) * Sum_{d|k} d*sigma(d) is an integer.at n=8A069520
- Numbers k such that k-1, k+1 and k^2+1 are prime numbers.at n=26A070155
- Numbers k such that A000010(k) divides A074639(k).at n=46A074645
- a(n) = Sum_{k=1..prime(n)-1} floor(k^3/prime(n)).at n=11A078837
- a(n) = floor(a(n-2)^2/a(n-1)) + a(n-1) + a(n-2), a(0) = 0, a(1) = 1, a(2) = 1, ...at n=17A096081
- a(n) = (2/(n-1))*a(n-1) + ((n+5)/(n-1))*a(n-2) with a(0)=0 and a(1)=1.at n=36A096338
- Numbers n such that the sum of the digits of n^phi(n) is divisible by n.at n=24A109660