16620
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 46704
- Proper Divisor Sum (Aliquot Sum)
- 30084
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4416
- Möbius Function
- 0
- Radical
- 8310
- Omega Function (Ω)
- 5
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 66
- 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
- Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 16 (most significant digit on right).at n=27A029509
- Trajectory of 1 under map n->43n+1 if n odd, n->n/2 if n even.at n=31A033977
- Smallest integer k such that 2^n is the largest power of two that is contained in 2^k as a proper substring.at n=25A046300
- Numbers k such that 291*2^k + 1 is prime.at n=31A053362
- This table shows the coefficients of combinatorial formulas needed for generating the sequential sums of p-th powers of tetrahedral numbers. The p-th row (p>=1) contains a(i,p) for i=1 to 3*p-2, where a(i,p) satisfies Sum_{i=1..n} C(i+2,3)^p = 4 * C(n+3,4) * Sum_{i=1..3*p-2} a(i,p) * C(n-1,i-1)/(i+3).at n=16A087107
- Number of partitions of n such that the least part occurs exactly four times.at n=48A097092
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (0, 0, 1), (0, 1, 1), (1, 0, -1)}.at n=8A150106
- Least number k having n representations as the sum of the minimal number of cubes A002376(k).at n=20A163490
- Triangle read by rows: T(n,k) is the number of weighted lattice paths in L_n having k returns to the horizontal axis (both from above and below). The members of L_n are paths of weight n that start at (0,0) , end on the horizontal axis and whose steps are of the following four kinds: an (1,0)-step with weight 1, an (1,0)-step with weight 2, a (1,1)-step with weight 2, and a (1,-1)-step with weight 1. The weight of a path is the sum of the weights of its steps.at n=37A182898
- Half the number of (n+1) X 2 0..2 arrays with every 2 X 2 subblock having two or three distinct clockwise edge differences.at n=3A210269
- Half the number of (n+1)X5 0..2 arrays with every 2X2 subblock having two or three distinct clockwise edge differences.at n=0A210272
- T(n,k)=Half the number of (n+1)X(k+1) 0..2 arrays with every 2X2 subblock having two or three distinct clockwise edge differences.at n=6A210276
- T(n,k)=Half the number of (n+1)X(k+1) 0..2 arrays with every 2X2 subblock having two or three distinct clockwise edge differences.at n=9A210276
- a(n) is the sum of all distinct integers that can be produced by reversing the digits of n in any base b >= 2.at n=55A211518
- Triangle T(n,k) of weakly graded (3+1)-free partially ordered sets (posets) on n labeled vertices with height k.at n=17A222866
- Number of (1+1) X (n+1) 0..1 arrays with no element having a strict majority of its horizontal and antidiagonal neighbors equal to one.at n=11A231998
- Partial sums of A301692.at n=99A301693
- Expansion of (theta_3(z)*theta_3(23z) + theta_2(z)*theta_2(23z))^5.at n=18A328093
- a(n) is the exponent of the least power of 2 such that the concatenated digits of the decimal expansion of 2^n are a proper substring of the concatenated digits of the decimal expansion of 2^a(n).at n=25A342575
- Difference between prime(Fibonacci(n+1)) and prime(Fibonacci(n)).at n=17A343256