13695
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 24192
- Proper Divisor Sum (Aliquot Sum)
- 10497
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6560
- Möbius Function
- 1
- Radical
- 13695
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- yes
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- yes
- 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
- 63
- 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
- a(n) = (2*n+1)*(4*n+1).at n=41A014634
- Numbers k such that sigma(k) = sigma(k+7).at n=18A015867
- Pseudoprimes to base 56.at n=43A020184
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 39.at n=34A031537
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 39.at n=2A031717
- Numbers whose base-4 representation contains exactly three 1's and four 3's.at n=15A045128
- Smallest triangular number beginning with the n-th triangular number other than itself.at n=15A072517
- a(1) = 0, then smallest triangular number such that a(n+1)- a(n) is a palindrome.at n=20A075057
- Numbers k such that iterating phi(sigma(k)-phi(k)) starting from k leads to the fixed point 8064.at n=33A077096
- Expansion of x^4*(2+x)/((1+x)*(1-x)^5).at n=19A082289
- Expansion of (1+x+x^2)/((1+x^2)*(1+x)^4*(1-x)^5).at n=39A082290
- Smallest triangular number > 1 and == 1 (mod prime(n)).at n=38A087397
- Smallest triangular number with Hamming weight n (i.e., with exactly n 1's when written in binary).at n=11A089999
- Hexagonal numbers with prime indices.at n=22A117961
- Numbers which are both lucky and triangular.at n=31A118565
- t(n)_n where t() = triangular numbers A000217.at n=40A122634
- a(1) = 1. If a(n) is prime, a(n+1) = 2*a(n); otherwise, a(n+1) = 2*a(n) + 1.at n=13A125049
- Triangular numbers t which are average of two consecutive primes p and p+4.at n=18A129752
- Triangular numbers which are the average of two consecutive primes.at n=37A130178
- a(n) = 5*n*(5*n + 1)/2.at n=33A144312