13039
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
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 15120
- Proper Divisor Sum (Aliquot Sum)
- 2081
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11136
- Möbius Function
- -1
- Radical
- 13039
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 81
- 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
- Number of partitions of n into parts not of the form 13k, 13k+4 or 13k-4. Also number of partitions with at most 3 parts of size 1 and differences between parts at distance 5 are greater than 1.at n=39A035952
- T(n,3), array T as in A054126.at n=8A054129
- T(n,n-4), where T is the array in A055830.at n=38A055831
- Numbers n such that phi(3n-1) = sigma(n).at n=46A067232
- Numbers n such that sigma(n)=phi(n*bigomega(n)-1).at n=29A067877
- Numbers m such that the positive values of m - A002110(k) are all primes (k > 0).at n=36A068372
- Composite k such that (k+1) * Sum_{d|k} d/sigma(d) is an integer.at n=10A068975
- Multiples of 13 containing a 13 in their decimal representation.at n=37A121033
- Define E(n) = Sum_{k>=0} (-1)^floor(k/3)*k^n/k! for n = 0,1,2,... . Then E(n) is an integral linear combination of E(0), E(1) and E(2). This sequence lists the coefficients of E(1).at n=10A143629
- a(n) = A168174(n)-10^12.at n=17A168248
- Smallest m such that A070965(m) = n.at n=34A227953
- Numbers n such that n*2^1279 - 1 is prime.at n=34A265502
- Nonprime numbers k such that the sum of the divisors of k^2 is of the form m^2 + m + 1.at n=27A289385
- Smallest m such that prime(3*n)# can be written as a product of n sphenic numbers each <= m.at n=6A337494