7229
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7230
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 7228
- Möbius Function
- -1
- Radical
- 7229
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 119
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 924
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Smallest nonnegative number that is the sum of 3 squares in exactly n ways.at n=35A000437
- Smallest number that is the sum of 3 squares in at least n ways.at n=35A000451
- Primes of form k^2 + 4.at n=17A005473
- From table of maximal epacts e(p) and corresponding primes p, for x_1=2, x_{m+1} = (x_m)^2+1; sequence gives p.at n=26A014424
- Primes that remain prime through 2 iterations of function f(x) = 8x + 7.at n=42A023263
- Primes that remain prime through 3 iterations of function f(x) = 8x + 7.at n=4A023294
- Primes with first digit 7.at n=41A045713
- Second term of strong prime 5-tuples: p(m)-p(m-1) > p(m+1)-p(m) > p(m+2)-p(m+1) > p(m+3)-p(m+2).at n=18A054809
- Indices of primes in sequence defined by A(0) = 33, A(n) = 10*A(n-1) + 23 for n > 0.at n=8A056254
- First member of a prime triple in a p^2 + p - 1 progression.at n=32A057324
- Duchon's numbers: the number of paths of length 5*n from the origin to the line y = 2*x/3 with unit East and North steps that stay below the line or touch it.at n=4A060941
- Numbers prime(k) such that A068863(k) = prime(k).at n=20A068868
- a(1)=1, a(2)=2, a(n+2)=(a(n+1)+a(n))/2 if a(n+1)+a(n) is even, a(n+2)=(3*(a(n+1)+a(n))+1)/2 otherwise.at n=18A069162
- Primes with either no internal digits or all internal digits are 2.at n=47A069677
- Squared radii of the spheres around (0,0,0) that contain record numbers of lattice points.at n=43A071609
- Take A000040, omit commas: 23571113171923..., select 4-digit primes seen when scanning from left.at n=23A073037
- Least m such that A078142(m) gives the n-th prime, where A078142(n) is the sum of the differences of the distinct prime factors p of n and the next square larger than p.at n=38A073939
- a(n) = 4*(n+1)*n + 5.at n=42A078370
- Duplicate of A068868.at n=20A085136
- a(n) = sum of the first n lower twin primes.at n=28A086167