7205
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9504
- Proper Divisor Sum (Aliquot Sum)
- 2299
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5200
- Möbius Function
- -1
- Radical
- 7205
- 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
- 163
- 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 that are the sum of 12 positive 7th powers.at n=41A003379
- Smallest positive number that can be written as sum of distinct Fibonacci numbers in n ways.at n=75A013583
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (1, p(1), p(2), ...), t = (F(2), F(3), F(4), ...).at n=13A025101
- Numbers k such that k divides the (left) concatenation of all numbers <= k written in base 16 (most significant digit on right and removing all least significant zeros before concatenation).at n=16A029533
- Number of upward triangles in a Star of David matchstick arrangement of size n.at n=11A045950
- Numbers of the form p*q*r where p,q,r are distinct odd palindromic primes (odd terms from A002385).at n=30A046405
- Number of 5-gonal compositions of n into positive parts.at n=24A069983
- Indices of primes of the form k^2 - 11.at n=36A091273
- A first order iteration: n-th term is obtained from (n-1)-th by adding n-th prime and then multiplying by the n-th prime; initial value is 1.at n=4A098206
- an=n-th smallest integer m=p1*p2*p3, product of 3 odd primes such that d+2m/d are all primes for d dividing 2m.at n=9A128278
- Number of partitions of n having standard deviation σ <= 2.at n=39A238659
- Number of partitions p of n such that (number of distinct parts of p) >= max(p) - min(p).at n=45A239958
- Number of 2 X n 0..3 arrays with no element equal to one plus the sum of elements to its left or two plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.at n=32A240001
- Number of inequivalent colorings of the Fano plane with n colors.at n=6A241929
- Number of unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 2.at n=15A244456
- Numbers m such that there are precisely 7 groups of order m.at n=21A249550
- Expansion of Sum_{i>=1} mu(i)^2*i*x^i/(1 - x^i) / Product_{j>=1} (1 - x^j), where mu() is the Moebius function (A008683).at n=18A281904
- Number of Dyck paths of semilength n such that the minimal number of peaks over all positive levels equals nine.at n=12A288548
- Numbers k such that (4*10^k - 79)/3 is prime.at n=17A289752
- Numbers k such that (7*10^k + 113)/3 is prime.at n=15A293591