13635
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 24480
- Proper Divisor Sum (Aliquot Sum)
- 10845
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7200
- Möbius Function
- 0
- Radical
- 1515
- Omega Function (Ω)
- 5
- 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
- 138
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Numbers that are the sum of 5 nonzero 8th powers.at n=13A003383
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Lucas numbers), t = (primes).at n=19A025098
- a(n) = (3*n - 1)*(4*n - 1).at n=34A033578
- Larger members of g-reduced amicable pairs a < b such that sigma(a) = sigma(b) = a + b + gcd(a,b).at n=31A054572
- a(n) = partitions(n)*partitions(n+1).at n=13A090982
- Numbers k for which nontrivial positive magic squares of exactly 9 different orders with magic sum k exist. For a definition of nontrivial positive magic squares, see A125005.at n=25A125016
- a(1) = 1, then partial products of Product_{n>=1} (p(n)/p(n-1)*p(n)/p(n-1)) = 1*1*1*(2)*(2)*(3/2)*(3/2)*(5/3)*(5/3)*(7/5)*(7/5)*...*; p = partition numbers, A000041 starting (1, 2, 3, 5, ...).at n=27A171646
- Number of zero-sum -6..6 arrays of n elements with first and second differences also in -6..6.at n=5A201871
- T(n,k)=Number of zero-sum -k..k arrays of n elements with first and second differences also in -k..k.at n=60A201873
- Number of zero-sum -n..n arrays of 6 elements with first and second differences also in -n..n.at n=5A201877
- Deficient numbers n having a companion m > n such that sigma(n)/n = sigma(m)/m.at n=23A212608
- a(n) = the number of integers i in {1,2,...,L}, where L = lcm(1,2,...,n), having the property that the number of positive integer divisors of i that are less than or equal to n, is odd.at n=10A241147
- a(n) = the number of integers i in {1,2,...,L}, where L = lcm(1,2,...,n), having the property that the number of positive integer divisors of i that are less than or equal to n, is odd.at n=11A241147
- First differences of 1/p(n), reciprocal of the number p(n) of unrestricted partitions of n (denominator).at n=13A272340
- 2*n analog to Keith numbers.at n=21A282757
- Sum of the prime parts in the partitions of n into 8 parts.at n=32A309469
- a(n) = 13*n^2 + 10*n + 3.at n=32A387659