16626
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
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 35424
- Proper Divisor Sum (Aliquot Sum)
- 18798
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5184
- Möbius Function
- 1
- Radical
- 16626
- 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
- 190
- 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
- Generalized Stirling numbers, [n+2,n]_2.at n=17A001701
- Triangle of up-down sums of k-th powers: a(n,k)=sum(i^k,i=1..n)+sum((n-i)^k,i=1..n-1), n,k>0.at n=49A051672
- a(n) = (2*n-1)*(n^2 -n +2)/2.at n=25A063488
- Cyclotomic polynomials Phi_n at x=phi, floored down (where phi = tau = (sqrt(5)+1)/2).at n=25A063703
- Cyclotomic polynomials Phi_n at x=phi, rounded to nearest integer (where phi = tau = (sqrt(5)+1)/2).at n=25A063705
- a(n) = n*(n-1)*(n^2 + 2)/6.at n=18A071244
- Maximum determinant that can be formed from the optimal set of nonnegative 3 X 3 matrix elements <=n, which maximize the number of different determinants given in A099834.at n=24A099815
- Number of (n+1) X 2 0..5 arrays with every 2 X 2 subblock summing to 10.at n=3A183654
- Number of (n+1) X 5 0..5 arrays with every 2 X 2 subblock summing to 10.at n=0A183657
- T(n,k) = Number of (n+1) X (k+1) 0..5 arrays with every 2 X 2 subblock summing to 10.at n=6A183662
- T(n,k) = Number of (n+1) X (k+1) 0..5 arrays with every 2 X 2 subblock summing to 10.at n=9A183662
- a(n) = n*(14*n + 13).at n=34A195028
- Numbers that are the sum of seven fourth powers in six or more ways.at n=6A345572
- Numbers that are the sum of seven fourth powers in exactly six ways.at n=6A345828
- a(n) = Sum_{k=0..n} (-1)^k * binomial(2*n, k) * (n-k)^(3*n).at n=3A383929
- a(n) is the least number x such that x^2 + 1 and 2^x + 1 are both divisible by A387595(n).at n=40A387642