13255
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
- 17424
- Proper Divisor Sum (Aliquot Sum)
- 4169
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9600
- Möbius Function
- -1
- Radical
- 13255
- 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
- 275
- 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
- Numbers k such that k, k+1, k+2 and k+3 have the same number of divisors.at n=15A006601
- In the '3x+1' problem, these values for the starting value set new records for number of steps to reach 1.at n=27A006877
- In the '3x+1' problem, these values for the starting value set new records for number of steps to reach 1.at n=21A033958
- a() = 1,3,... [ A037257 ], differences = 2,... [ A037258 ] and 2nd differences [ A037259 ] are disjoint and monotonic; adjoin next free number to 2nd differences unless it would produce a duplicate in which case ignore.at n=37A037257
- Convolution of L(n+1) := A000204(n+1) (Lucas), n>=0, with L(n+5), n>=0.at n=9A067983
- Composite n such that (n-1)*phi(n) is a perfect square.at n=21A069953
- Number of prime pairs below 10^n having a difference of 28.at n=6A093749
- Total number of odd parts in the last section of the set of partitions of n.at n=32A206433
- Triangle of coefficients of polynomials v(n,x) jointly generated with A209419; see the Formula section.at n=61A209420
- Expansion of (1+4*x+x^2)/((1+x)^2*(1-x)^5).at n=19A233329
- Numbers m such that there are precisely 7 groups of order m.at n=48A249550
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 825", based on the 5-celled von Neumann neighborhood.at n=22A273581
- Number of endofunctions on [n] whose cycle lengths are primes.at n=6A273998
- Numbers k such that (2*10^k - 71)/3 is prime.at n=22A280449
- Least integer k such that k/2^n > (1+sqrt(5))/2 (the golden ratio).at n=13A293314
- The integer k that minimizes |k/2^n - r|, where r = golden ratio.at n=13A293315
- Expansion of Product_{k>=1} (1 + x^k) * (1 + x^(2*k)) * (1 + x^(3*k)).at n=34A327045
- Expansion of (1 / theta_4(x) - 1)^3 / 8.at n=9A341364
- Composite numbers k such that A006577(k) sets a new record.at n=22A346591
- Number of integer partitions of n without all different sums of two-element submultisets.at n=37A366753