7870
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14184
- Proper Divisor Sum (Aliquot Sum)
- 6314
- 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
- 3144
- Möbius Function
- -1
- Radical
- 7870
- 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
- 101
- 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
- Molien series for A_6.at n=46A008629
- a(n) = floor( n*(n-1)*(n-2)/20 ).at n=55A011902
- Number of partitions satisfying (cn(0,5) = 0 and cn(2,5) <= cn(1,5) and cn(3,5) <= cn(1,5) and cn(2,5) <= cn(4,5) and cn(3,5) <= cn(4,5)).at n=45A036806
- Denominators of continued fraction convergents to sqrt(545).at n=7A042043
- Numbers whose base-4 representation contains exactly three 2's and three 3's.at n=32A045151
- Number of ways to cover (without overlapping) a ring lattice (necklace) of n sites with molecules that are 8 sites wide.at n=42A058365
- Nearest integer to (Product(n^((1 + log(1 + i))/i^2), {i, 1, n})).at n=17A062487
- Numbers k such that reverse(k) is a prime factor of k.at n=45A072299
- Interprimes which are of the form s*prime, s=10.at n=20A075285
- Numbers n such that 4^n+3^(n-1) is prime.at n=31A093717
- Numbers n such that more than half of the reduced-residue system modulo 210 consists of primes in the following sense: in {210n + R} more than 24 = phi(210)/2 primes occur, i.e., 25-33, 35, 46.at n=55A095392
- Antidiagonal sums of rectangular table A124560.at n=8A124561
- Number of compositions of n such that every part divides the largest part.at n=16A130708
- Triangle read by rows, T(n,k) = (2^k-1) * T(n-1,k) + T(n-1,k-1).at n=24A139382
- Triangle T(n,k,2) read by rows (generalized q-Stirling numbers of second kind): T(n, k, q_) = (1/(q - 1)^k)*Sum[(-1)^(k - j)*q*Binomial[k + n, k -j] - Binomial[j + n, j, q - 1], {j, 0, k}], with q=2, where Binomial[,] is the Gaussian q-binomial coefficient as in A022166.at n=13A156823
- The number of different classes of 2-dimensional convex lattice polytopes having volume n/2 up to unimodular equivalence.at n=35A187015
- Number of nX5 0..1 arrays with no more than floor(nX5/2) elements unequal to at least one king-move neighbor, with new values introduced in row major 0..1 order.at n=5A222357
- Number of nX6 0..1 arrays with no more than floor(nX6/2) elements unequal to at least one king-move neighbor, with new values introduced in row major 0..1 order.at n=4A222358
- T(n,k)=Number of nXk 0..1 arrays with no more than floor(nXk/2) elements unequal to at least one king-move neighbor, with new values introduced in row major 0..1 order.at n=49A222360
- T(n,k)=Number of nXk 0..1 arrays with no more than floor(nXk/2) elements unequal to at least one king-move neighbor, with new values introduced in row major 0..1 order.at n=50A222360