16172
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 30576
- Proper Divisor Sum (Aliquot Sum)
- 14404
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7440
- Möbius Function
- 0
- Radical
- 8086
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- yes
- 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
- 27
- 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 k such that 6!*(2*k-7)!/(k!*(k-1)!) is an integer.at n=17A004786
- Numbers k such that 7!*(2k-8)!/(k!*(k-1)!) is an integer.at n=19A004787
- [ (4th elementary symmetric function of S(n))/(2nd elementary symmetric of S(n)) ], where S(n) = {3,4, ..., n+5}.at n=25A024194
- First differences of A002002.at n=5A035028
- Number of pairs of sets of cardinality at least 3.at n=14A052516
- Convolution of A055589 with A011782.at n=8A055852
- Successive maxima in sequence A007365.at n=8A065933
- Number of horizontal segments in all Schroeder paths of length 2n (a horizontal segment is a maximal string of horizontal steps).at n=6A104550
- Pentagonal numbers (A000326) whose digit reversal is a brilliant number (A078972).at n=10A115680
- Pentagonal numbers (A000326) whose digit reversal is a semiprime (A001358).at n=31A115709
- Pentagonal numbers (A000326) which are the sum of 2 other positive pentagonal numbers.at n=23A136117
- Values of n such that (sigma(sigma(n))-phi(phi(n)))/n is an integer (the corresponding integral ratios are given in A136132).at n=23A136131
- a(n)=Sum((A008292(n - j, j) - C(n - j - 1, j))/2, j=0, [(n - 1)/2]).at n=11A174958
- The number of ways of putting n labeled items into k labeled boxes so that each box receives at least 3 objects.at n=27A200092
- Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and w+2x+2y>0.at n=16A211624
- Number of paths from (0,0) to the line x = n, each segment given by a vector (1,1), (1,-1), or (2,0), not crossing the x-axis, and including no horizontal segment on the x-axis.at n=13A247630
- Pentagonal numbers divisible by 4.at n=26A298397
- a(n) is the Wiener index of a sling on n+1 vertices.at n=45A349417
- Triangle read by rows T(n, k) is the number of permutations on n elements whose square has k descents, for n >= 1 and 0 <= k <= n-1.at n=31A373691
- Let P(m,k) = 1-(m-1)*...*(m-k+1)/m^(k-1) be the probability that at least two out of k people share a birthday out of m possible days. Sequence gives values of m for which P(m,k(m)) sets a new minimum, where k(m) is the smallest k such that P(m,k) > 1/2.at n=12A392222