7615
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9144
- Proper Divisor Sum (Aliquot Sum)
- 1529
- 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
- 6088
- Möbius Function
- 1
- Radical
- 7615
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 57
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Number of ordered 5-tuples of integers from [ 2,n ] with no common factors among quadruples.at n=14A015655
- Numbers k such that the continued fraction for sqrt(k) has period 68.at n=24A020407
- Sums of five consecutive squares: a(n) = n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2.at n=37A027578
- Sums of 11 distinct powers of 2.at n=35A038462
- Numbers k such that sigma(k) divides sigma(k+1), where sigma(k) is sum of positive divisors of k.at n=18A058072
- Numbers k such that gcd(sigma(k), sigma(k+1)) > k.at n=26A066025
- Numbers k such that sigma(k+1) = 2*sigma(k).at n=6A067081
- Average of four successive primes squared, (prime(n)^2 + prime(n+1)^2 + prime(n+2)^2 + prime(n+3)^2)/4, n>=2.at n=20A075894
- Numbers k such that there are exactly 8 numbers j for which binomial(k, floor(k/2)) / binomial(k,j) is an integer, i.e., A080383(k) = 8.at n=43A080386
- Numbers k such that 5*10^k + 2*R_k + 1 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=14A103009
- Values of the exponents in A084435.at n=14A113767
- Numbers k such that the numerator of Sum_{j=1..k} k^2/(2*j*(j+k)) is prime.at n=40A125745
- Number of 2 X 2 singular integer matrices with entries from {2,...,n}.at n=43A134978
- Similar to A072921 but starting with 5.at n=37A152234
- a(n) = Least i in range [A165583(n),A165583(n+1)] for which abs(A165582(i)) gets the maximum value in that range.at n=29A165584
- Integers of the form 4n+3 for which Sum_{i=1..u} J(i,4n+3) obtains value zero exactly 9 times, when u ranges from 1 to (4n+3). Here J(i,k) is the Jacobi symbol.at n=24A166059
- Wiener index of a benzenoid consisting of a double-step spiral chain of n hexagons (n>=2, s=21; see the Gutman et al. reference).at n=9A193397
- Number of triples (w,x,y) with all terms in {0,...,n} and |w-x| + |x-y| <= w+x+y.at n=19A213481
- Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths ending at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 4, n >= 2.at n=50A214122
- Number of (n+2)X(4+2) 0..1 arrays x(i,j) with every row sum{j*x(i,j), j=1..4+2} equal, and every column sum{i*x(i,j), i=1..n+2} equal, with upper left element zero.at n=11A232650