7222
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 11376
- Proper Divisor Sum (Aliquot Sum)
- 4154
- 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
- 3432
- Möbius Function
- -1
- Radical
- 7222
- 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
- 70
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers k for which 10k+1, 10k+3, 10k+7 and 10k+9 are primes.at n=29A007811
- Coordination sequence for CaF2(2), F position.at n=38A009925
- a(0) = 1, a(n) = 5*n^2 + 2 for n>0.at n=38A010001
- a(0) = 1, a(n) = 20*n^2 + 2 for n>0.at n=19A010010
- a(n) = Sum_{k=0..n} ceiling(k^3/n).at n=29A014813
- Number of triples (i,j,k) with 1 <= i < j < k <= n and gcd(i,j,k) = 1.at n=37A015616
- Numbers having three 6's in base 8.at n=34A043447
- Numbers having three 2's in base 10.at n=33A043499
- a(n) = T(2n-1,n), array T given by A048201.at n=42A048208
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 24.at n=38A051989
- Number of rooted identity trees with n nodes and 3 leaves.at n=21A055328
- Largest number whose digit product equals n; a(n)=0 if no such number exists, e.g., when n has a prime factor larger than 7; no digit=1 is permitted to avoid an infinite number of solutions.at n=55A068190
- Replace n with concatenation of its prime factors in decreasing order.at n=55A084796
- Greatest number formed by concatenating prime factors of n in base 10.at n=55A084797
- a(0)=1; a(n) = sigma_2(n) + sigma_3(n).at n=19A092344
- If n <= 1 then n else smallest number having in decimal representation exactly one common digit with its predecessor but none with its pre-predecessor.at n=40A107277
- Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 11011-01110-00100 pattern in any orientation.at n=15A147487
- Number of binary strings of length n with no substrings equal to 0001 0101 or 1110.at n=18A164475
- Number of minimally rigid graphs in 2D on n vertices.at n=8A227117
- Number of n X 4 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.at n=1A233213