16969
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17280
- Proper Divisor Sum (Aliquot Sum)
- 311
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16660
- Möbius Function
- 1
- Radical
- 16969
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 84
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Number of prime unlabeled T_0 topologies (i.e., prime T_0 homeomorphism classes) on n points.at n=6A028856
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 80 ones.at n=12A031848
- Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 2,1,0,3.at n=5A037732
- Numbers having four 1's in base 8.at n=31A043428
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = a(3) = 1.at n=41A050027
- Take pairs (a, b), sorted on a, such that T(a)+T(b)=concatenation of a and b, where T(k) is the k-th triangular number A000217(k). Sequence gives values of a.at n=27A096031
- 288*n^2 - 168*n - 119.at n=7A118059
- The least nonsquare number s having exactly n twos in the periodic part of the continued fraction of sqrt(s).at n=41A206582
- Numbers n such that the decimal number concat(3,n) is a square.at n=40A273358
- First differences of A293160.at n=23A295783
- The number of ways of placing 2n-1 white balls and 2n-1 black balls into unlabeled bins such that each bin has both an odd number of white balls and black balls.at n=11A302919
- Numbers of the form Product_{k=i..j} prime(k) - Sum_{k=i..j} prime(k) where i < j.at n=44A387946