7894
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11844
- Proper Divisor Sum (Aliquot Sum)
- 3950
- 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
- 3946
- Möbius Function
- 1
- Radical
- 7894
- 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
- 189
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = floor(Sum_{1<=i<j<=n} (sqrt(j)-sqrt(i))^2).at n=51A025196
- a(n) = T(2n,n+1), where T is the array in A026268.at n=5A026296
- a(n) = least k such that 1+2+...+k >= E{1,2,...,n}, where E is the 3rd elementary symmetric function.at n=31A027917
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 88.at n=11A031586
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 44 ones.at n=27A031812
- Expansion of q^(-3) * (eta(q) * eta(q^8))^8 in powers of q.at n=36A034433
- Number of partitions of n into parts not of the form 13k, 13k+6 or 13k-6. Also number of partitions with at most 5 parts of size 1 and differences between parts at distance 5 are greater than 1.at n=36A035954
- a(n) = Sum_{i=0..2n} (-1)^i * T(i,2n-i), array T as in A049723.at n=35A049725
- Numbers k that, when expressed in base 5 and then interpreted in base 7, give a multiple of k.at n=7A062929
- Semiprimes in A103376.at n=18A103396
- Positions of 9 in partition of decimal expansion of Pi A104807.at n=27A104809
- Numbers k such that k and 8*k, taken together, are zeroless pandigital.at n=24A115932
- A version of F. K. Hwang's sequence in {3*k, 3*k+1, 3*k+2}.at n=35A123945
- Record indices of the ratio A002375(n) / n (Goldbach conjecture related).at n=32A137820
- a(n) = Sum_{d|n} A007955(d) * A008683(n/d) = Sum_{d|n} A007955(d) * mu(n/d), where A007955(m) = number of divisors of m.at n=19A174940
- Trajectory of 80 under the map n-> A006368(n).at n=25A223087
- Minimum even value unattainable as the sum of 6 attained values of i*(i-1) with i in 0..n.at n=38A225292
- Number of isoscent sequences of length n with exactly nine ascents.at n=1A243235
- Number of isoscent sequences of length n with maximal number of ascents.at n=15A243237
- Number of length n+6 0..1 arrays with at most one downstep in every n consecutive neighbor pairs.at n=26A255997