15690
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 37728
- Proper Divisor Sum (Aliquot Sum)
- 22038
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4176
- Möbius Function
- 1
- Radical
- 15690
- 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
- 177
- 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
- Numbers that are the sum of 3 nonzero 6th powers.at n=21A003359
- Numbers that are the sum of at most 3 nonzero 6th powers.at n=39A004854
- a(n) = 1^n + 2^n + 5^n.at n=6A074501
- a(n) = floor(sqrt(a(n-1)^2 + a(n-2)^2)), a(1)=100, a(2)=300.at n=18A104908
- Number of polyenes with 2n carbon atoms.at n=10A135527
- a(n) = Sum_{k=0..n} (-1)^(n-k)*C(n,k)*sigma(n,k) for n>0 with a(0)=1.at n=6A163191
- First string of 43 consecutive composite numbers.at n=6A177949
- Super anti-perfect numbers.at n=7A192275
- Sum of distinct nonzero sixth powers.at n=18A194769
- The number of 2 X 2 symmetric positive definite matrices whose entries are integers x,y,z satisfying x^2 + y^2 + z^2 <= n^2.at n=31A219744
- Integer lengths of log(2)-primes: numbers n such that the concatenation of the first n decimal digits of log(2) is prime.at n=3A228226
- Let sigma*_m (n) be result of applying sum of anti-divisors m times to n; call n (m,k)-anti-perfect if sigma*_m (n) = k*n; sequence gives the (2,k)-anti-perfect numbers.at n=25A229860
- 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=37A230358
- Numbers equidistant from twin prime pairs that are also equidistant from numbers equidistant from twin prime pairs.at n=21A260517
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 483", based on the 5-celled von Neumann neighborhood.at n=27A267829
- 38-gonal numbers: a(n) = n*(18*n-17).at n=30A282850
- a(n) is the smallest number k such that the difference between the next prime greater than k and k equals n.at n=36A309877
- Number of colored compositions of n using all colors of a 2-set such that all parts have different color patterns and the patterns for parts i are sorted and have i colors in (weakly) increasing order.at n=11A327841
- Number of edges in a Farey fan of order n.at n=42A360043