13345
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 17064
- Proper Divisor Sum (Aliquot Sum)
- 3719
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9984
- Möbius Function
- -1
- Radical
- 13345
- Omega Function (Ω)
- 3
- 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
- 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
- 169
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Pseudoprimes to base 12.at n=40A020140
- Pseudoprimes to base 13.at n=34A020141
- Pseudoprimes to base 28.at n=37A020156
- Multiplicity of highest weight (or singular) vectors associated with character chi_150 of Monster module.at n=39A034538
- Number of partitions satisfying (cn(2,5) = cn(3,5) and cn(0,5) <= cn(1,5) and cn(0,5) <= cn(4,5) and cn(2,5) <= cn(1,5) and cn(2,5) <= cn(4,5)).at n=51A036811
- The sequence e when b=[ 1,0,1,1,1,... ].at n=39A042953
- Sum of factorials of digits of n equals the largest prime factor of n.at n=13A074257
- Numbers n such that p(5n) is prime, where p(n) is the number of partitions of n.at n=32A114166
- a(n) = 11^n - 6^n.at n=4A139744
- Differences of two coprime 4th powers.at n=40A147858
- Number of (n+2) X 3 binary arrays with every 3 X 3 subblock commuting with each horizontal and vertical neighbor 3 X 3 subblock.at n=14A190025
- Number of n X 2 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.at n=4A202883
- Number of nX5 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.at n=1A202886
- T(n,k)=Number of nXk 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.at n=16A202889
- T(n,k)=Number of nXk 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.at n=19A202889
- G.f.: exp( Sum_{n>=1} A001333(n)^2 * x^n/n ) where A001333(n) = A002203(n)/2, one-half the companion Pell numbers.at n=7A204061
- Smallest k > 0 such that (5^n+k)*5^n-1 and (5^n+k)*5^n+1 are a twin prime pair.at n=28A212487
- a(n) = n*(3*n^2 - 5*n + 3).at n=17A226450
- Number of n X 4 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.at n=6A229424
- Number of nX7 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.at n=3A229427