16999
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 34
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17280
- Proper Divisor Sum (Aliquot Sum)
- 281
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16720
- Möbius Function
- 1
- Radical
- 16999
- 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
- yes
- 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 partially ordered sets ("posets") with n unlabeled elements.at n=8A000112
- a(n) = floor(phi*a(n-1)) + a(n-2) where phi is the golden ratio.at n=13A005830
- Number of partitions satisfying cn(0,5) <= cn(1,5) + cn(4,5).at n=36A039839
- Composite numbers whose divisors (except 1) all contain the digit 9.at n=27A062680
- Triangle T(n,k) read by rows of partially ordered sets ("posets") with n unlabeled nodes and k maximal elements (0 <= k <= n).at n=46A065066
- "Canada perfect numbers": n such that the sum of digits^2 of n equals the sum of d|n, 1<d<n.at n=3A070308
- Numbers n such that A001414(n) = sum of squared digits of n.at n=32A094908
- Difference between squares of legs of primitive Pythagorean triangles, sorted (with multiplicity).at n=32A127923
- Least number k such that A070635(k) = n.at n=33A138791
- Numbers n such that sum of squares of digits of n equals the sum of prime divisors of n.at n=35A217390
- Number of (n+1) X (1+1) 0..2 arrays with the upper median equal to the lower median in every 2 X 2 subblock.at n=4A235974
- Number of (n+1)X(5+1) 0..2 arrays with the upper median equal to the lower median in every 2X2 subblock.at n=0A235978
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the upper median equal to the lower median in every 2X2 subblock.at n=10A235981
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the upper median equal to the lower median in every 2X2 subblock.at n=14A235981
- Numbers for which the root mean square of nontrivial divisors is an integer and which are not a square of prime numbers.at n=32A247137
- a(n) gives the odd leg of the second of the two Pythagorean triangles with hypotenuse A080109(n) = A002144(n)^2. This is the larger of the two possible odd legs.at n=15A253804
- Numbers whose arithmetic derivative is equal to the sum of some fixed power of their digits.at n=9A269719
- Numbers k such that the Reverse and Add! trajectory of k (presumably) does not reach a palindrome and does not join the trajectory or one of the reverse numbers of the trajectory of any term m < k.at n=38A306232
- Number of integer partitions of n containing all divisors of all parts.at n=43A371178
- Composite numbers that contain only nonprime digits and whose prime factors contain only nonprime digits.at n=34A383934