8188
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 15120
- Proper Divisor Sum (Aliquot Sum)
- 6932
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3872
- Möbius Function
- 0
- Radical
- 4094
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 158
- 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) = n*(31*n-1)/2.at n=23A022288
- a(n) = 2^n - 4.at n=11A028399
- Numbers having three 8's in base 10.at n=9A043523
- a(n) is twice the smallest k such that A051686(k) = prime(n).at n=36A051692
- Twice the positions in A051686 at which new primes appear in that sequence.at n=34A051861
- Triangle formed by right-bounded rhombus rule, read by rows.at n=62A059397
- Sum of terms in row n of A081532.at n=21A081533
- Indices of primes in sequence defined by A(0) = 29, A(n) = 10*A(n-1) - 51 for n > 0.at n=16A101956
- Sum of odd-indexed terms of tribonacci numbers.at n=8A113301
- Integers i such that 17*i = 49 X i.at n=43A115809
- a(n) = Sum_{k=0..n} floor(C(n,k)/2).at n=14A120739
- Number of pairs of probabilistically independent subsets in a set composed of n elements.at n=11A121312
- Number of 3-decomposable trees on 3n nodes.at n=4A121516
- Numbers k for which 16*k+1, 16*k+3 and 16*k+15 are primes.at n=34A123997
- Residues of 3^(2^(p(n)-1)) for Mersenne numbers with prime indices.at n=5A131459
- Triangle read by rows: T(n,k) is the number of paths in the first quadrant from (0,0) to (n,k), consisting of steps U=(1,1), D=(1,-1), h=(1,0) and H=(2,0) (0<=k<=n).at n=58A132276
- Positive numbers of the form x^4 - 6 * x^2 * y^2 + y^4 (where x,y are integers).at n=24A135789
- 2^n - number of digits of 2^n.at n=13A139817
- Number of planar triangular n X n X n nonnegative integer grids with every similarly oriented 4 X 4 X 4 subtriangle summing to 4.at n=3A154042
- Diagonal sums of Riordan array A154948.at n=15A154949