13169
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14196
- Proper Divisor Sum (Aliquot Sum)
- 1027
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12144
- Möbius Function
- 1
- Radical
- 13169
- 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
- 138
- 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
- a(n) is the decimal concatenation of n and n^2.at n=12A053061
- Numbers k such that x^k + x^8 + 1 is irreducible over GF(2).at n=9A057478
- Smallest composite number n such that every divisor > 1 includes n as a substring.at n=13A105582
- Semiprimes k=p*q such that the polynomial (1+x)^k (mod k) has p+q nonzero terms.at n=40A116926
- a(n) = A000265(3*(a(n-1) + a(n-2))/2 + 1) starting at a(1)=1, a(2)=11.at n=25A124139
- 1/16 the number of (n+1) X 3 0..7 arrays with every 2 X 2 subblock strictly increasing clockwise or counterclockwise with one decrease, and at least two adjacent blocks having the same increasing direction.at n=2A183731
- 1/16 the number of (n+1) X 4 0..7 arrays with every 2 X 2 subblock strictly increasing clockwise or counterclockwise with one decrease, and at least two adjacent blocks having the same increasing direction.at n=1A183732
- T(n,k) = 1/16 the number of (n+1) X (k+1) 0..7 arrays with every 2 X 2 subblock strictly increasing clockwise or counterclockwise with one decrease, and at least two adjacent blocks having the same increasing direction.at n=7A183738
- T(n,k) = 1/16 the number of (n+1) X (k+1) 0..7 arrays with every 2 X 2 subblock strictly increasing clockwise or counterclockwise with one decrease, and at least two adjacent blocks having the same increasing direction.at n=8A183738
- Number of strings of numbers x(i=1..7) in 0..n with sum i*x(i)^3 equal to 7*n^3.at n=16A184724
- Number of 0..5 arrays of length n with each element differing from at least one neighbor by 1 or less, starting with 0.at n=7A221680
- Number of length n 1..(2+2) arrays with no leading or trailing partial sum equal to a prime.at n=12A254198
- Concatenation of prime(n) and its square.at n=5A271422
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 429", based on the 5-celled von Neumann neighborhood.at n=25A272113
- Expansion of Product_{k>=1} ((1 + x^(4*k)) / (1 - x^k))^k.at n=16A285460