17642
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 26466
- Proper Divisor Sum (Aliquot Sum)
- 8824
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8820
- Möbius Function
- 1
- Radical
- 17642
- 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
- 48
- 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
- yes
- Odd
- no
Appears in sequences
- Number of points on surface of cuboctahedron (or icosahedron): a(0) = 1; for n > 0, a(n) = 10n^2 + 2. Also coordination sequence for f.c.c. or A_3 or D_3 lattice.at n=42A005901
- a(0) = 1, a(n) = 40*n^2 + 2 for n>0.at n=21A010022
- Numbers k such that the continued fraction for sqrt(k) has period 61.at n=27A020400
- Number of partitions of n into parts not of the form 21k, 21k+5 or 21k-5. Also number of partitions with at most 4 parts of size 1 and differences between parts at distance 9 are greater than 1.at n=38A035983
- Triangle defined in A064641 read by rows.at n=41A064642
- 2*3*5*6*...*a(n) -+ 1 are primes, with a(n+1) > a(n).at n=41A087900
- Coefficients of numerators of rational functions whose binomial transforms give the normalized polylogarithms Li(-n,t)/n!.at n=24A131758
- Numbers which converge to 2592 under repeated application of the powertrain map of A133500.at n=14A135384
- Composite numbers whose concatenation of their aliquot parts, in ascending order, is a palindrome.at n=31A249300
- Number of (n+2) X (4+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=18A252715
- Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 201", based on the 5-celled von Neumann neighborhood.at n=15A279806