15686
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 27648
- Proper Divisor Sum (Aliquot Sum)
- 11962
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6600
- Möbius Function
- 1
- Radical
- 15686
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 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
- yes
- Odd
- no
Appears in sequences
- Number of ways in which n identical balls can be distributed among 7 boxes in a row such that each pair of adjacent boxes contains at least 4 balls.at n=8A005340
- Number of Twopins positions.at n=16A005682
- (n,3,5) difference families over Z_n.at n=8A011995
- B referred to in A056600.at n=3A069717
- a(n) = n * [1 + sum(k=1 to n-1) prime(k)].at n=22A083719
- Greatest number m with A088444(m) = n.at n=30A088448
- Number of plane partitions of n with 3 or more columns.at n=16A089924
- Sums of the products of n consecutive pairs of numbers.at n=22A135036
- Consider the first run of composites that contains at least two numbers whose largest prime factor is prime(n), n >= 2. a(n) is the first of these numbers.at n=9A137799
- 11 times pentagonal numbers: 11*n*(3n-1)/2.at n=31A153449
- G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) * (1-x^18) * (1-x^21) * (1-x^24) / (1-x)^8.at n=10A162596
- Number of binary strings of length n with equal numbers of 000 and 001 substrings.at n=16A164137
- First string of 43 consecutive composite numbers.at n=2A177949
- a(n) = Sum_{d|n} d * sigma(n/d, d).at n=24A198302
- Multiples of 682.at n=23A200860
- a(n) = Sum_{k=1..n} binomial(n,k) * sigma(n,k) * (-1)^(n-k).at n=5A206764
- prime(n^2) - prime(n).at n=42A213926
- Minimal number (in decimal representation) with n nonprime substrings in base-5 representation (substrings with leading zeros are considered to be nonprime).at n=22A217105
- a(n) is the smallest number k > 0 such that k, k + 1, ... , k + n - 1 are nonprime numbers, but k + n is prime.at n=41A230358
- Number of length 3 0..n arrays with each partial sum starting from the beginning no more than one standard deviation from its mean.at n=34A244791