7315
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 11520
- Proper Divisor Sum (Aliquot Sum)
- 4205
- 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
- 4320
- Möbius Function
- 1
- Radical
- 7315
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- yes
- 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
- 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
- Binomial coefficient binomial(n,4) = n*(n-1)*(n-2)*(n-3)/24.at n=22A000332
- Number of compositions of n into 5 ordered relatively prime parts.at n=18A000743
- a(n) = binomial coefficient C(2n, n-7).at n=4A004313
- Binomial coefficient C(22,n).at n=4A010938
- Binomial coefficient C(22,n).at n=18A010938
- a(n) = binomial(n,18).at n=4A010971
- a(n) = floor(n*(n-1)*(n-2)/24).at n=57A011842
- Orders of cyclotomic polynomials containing a coefficient the absolute value of which is >= 5.at n=35A013593
- Triangular array formed from odd elements to right of middle of rows of Pascal's triangle.at n=56A014475
- Odd pentagonal numbers.at n=35A014632
- Binomial coefficients: C(n,k), 4 <= k <= n-4, sorted, duplicates removed.at n=27A024756
- a(n) = least m such that if r and s in {1/1, 1/4, 1/7, ..., 1/(3n-2)} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=38A024836
- a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n-k+1), where k = floor(n/2), s = (natural numbers), t = (natural numbers >= 3).at n=41A024854
- a(n) = n*(n^3 - 1)/2.at n=9A027482
- Quasi-Carmichael numbers to base 3: squarefree composites n such that prime p|n ==> p-3|n-3.at n=5A029560
- Denominator of Bernoulli(2n+2) - Bernoulli(2n).at n=9A029763
- Number of proper factorizations of p1^n*p2^3, where p1 and p2 are distinct primes.at n=16A031126
- Pentagonal numbers with even index.at n=35A049452
- Numbers k such that phi(k)*d(k) is a multiple of sigma(k), where d(k) is the number of divisors of k.at n=29A050934
- a(n) = binomial(n, floor(n/5)).at n=22A051052