7922
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
- 8
- Divisor Sum
- 12636
- Proper Divisor Sum (Aliquot Sum)
- 4714
- 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
- 3712
- Möbius Function
- -1
- Radical
- 7922
- 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
- 52
- 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
- Powers of sqrt(13) rounded up.at n=7A017945
- Powers of fourth root of 13 rounded up.at n=14A018083
- Coordination sequence for root lattice B_3.at n=20A022145
- a(n) = Sum_{d|Fibonacci(n)} d^2.at n=10A063478
- Numbers k such that the product of the digits of k is equal to the sum of the prime factors of k, counted with multiplicity.at n=24A065774
- a(n) = prime(n)^2 + 1.at n=23A066872
- Numbers n such that the sum of the prime factors of n equals the product of the digits of n.at n=20A067173
- Centered square numbers: a(n) = 4*n^2 + 4*n + 2.at n=44A069894
- Concatenation of n-th prime and n in decimal notation.at n=21A075110
- Triangle of binary products of Fibonacci numbers.at n=50A094568
- Bisection of A001157: a(n) = sigma_2(2n-1).at n=44A099978
- Number of rooted trees with total weight n, where the weight of a node at height k is k (with the root considered to be at level 1).at n=48A117357
- Expansion of phi(q)^2*psi(q)^4 in powers of q where phi(),psi() are Ramanujan theta functions.at n=44A122854
- Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and pyramid weight k.at n=39A129163
- Expansion of q^(-1/2) * (eta(q)^4 * eta(q^4)^2 / eta(q^2)^3)^2 in powers of q.at n=44A138502
- Twice nonagonal numbers (or twice 9-gonal numbers): a(n) = n*(7*n-5).at n=34A139268
- List of different composite numbers in Pascal-like triangles with index of asymmetry y = 1 and index of obliqueness z = 0 or z = 1.at n=40A141065
- a(n)= Number of distinct prime divisors (taken together) of numbers of the form 2x^2-1 for x<=10^n.at n=3A143868
- Number of permutations of length n which avoid the patterns 2341 and 3421.at n=8A165545
- Numbers of the form q-p, where p and q are prime and q = p^0+p^1+p^2+..+p^k for some k.at n=12A166388