13117
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14140
- Proper Divisor Sum (Aliquot Sum)
- 1023
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12096
- Möbius Function
- 1
- Radical
- 13117
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 107
- 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 concatenation of n and 9n.at n=12A009474
- a(n) = floor(exp(22/23) * n!).at n=6A030807
- Numbers k such that sopf(k) = (1/2)*(sopf(k+1) + sopf(k-1)), where sopf(x) = sum of the distinct prime factors of x.at n=9A075846
- Given a(1), ..., a(n-1), a(n) is minimal such that all terms of the sequence are distinct positive integers and, for all k>=1, the sum of the k terms from a(k) to a(2k-1) is a k-th power.at n=16A076992
- Smallest multiple of n beginning with n and having a digit sum n, or 0 if no such number exists.at n=12A077727
- Numbers k such that (k / sum of digits of k) and (k+1 / sum of digits of k+1) are both prime.at n=18A085775
- For a string of letters of length k, say abc...def, let f(k) be the string of length k-1 consisting of the adjacent pairs ab, bc, cd, ..., de, ef. Given n, let U be the string of length 2n consisting of n 1's followed by n 2's: 11...122...2. Then a(n) is the number of the C(2n,n) permutations V of U such that f(U) and f(V) agree in exactly one place.at n=9A098813
- Number of squares in the interior of the square with vertices (n,0), (0,n), (-n,0) and (0,-n) in a square (x,y)-grid.at n=26A111746
- Lucky numbers for which both the sum of the digits and the product of the digits is also a lucky number.at n=24A118559
- Numerator of Euler(n, 7/27).at n=3A157160
- Number of nXnXn 0..6 triangular arrays with each element x equal to the number its neighbors equal to 3,3,1,1,0,0,0 for x=0,1,2,3,4,5,6.at n=5A197705
- Least k > 1 such that n*(k*n-1) - 1 divides n^(k*n-1) - 1, or 0 if no such k exists.at n=14A273772
- Indices of primes in A026007.at n=39A285223
- Number of compositions of n with distinct differences up to sign.at n=23A325552
- In a Kolakoski n-chain, point at which term of penultimate sequence seq(n-1) differs from term of final sequence seq(n) in chain, when terms of seq(i) are run-lengths of seq(i+1) and the chain contains n sequences.at n=23A327421
- Numbers that can be represented in more than one way as p^2+p*q+q^2 with p and q primes, p<=q.at n=11A349987
- a(n) is the smallest number which can be represented as the sum of n distinct positive Fibonacci numbers (1 is allowed twice as a part) in exactly n ways, or -1 if no such number exists.at n=14A359391
- Odd semiprimes k = p*q such that k = A325820(p,q), with p, q primes > 3, and A325820 is the carryless base-3 multiplication.at n=38A391331