7858
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
- 11790
- Proper Divisor Sum (Aliquot Sum)
- 3932
- 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
- 3928
- Möbius Function
- 1
- Radical
- 7858
- 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
- 101
- 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
- Number of two-rowed partitions of length 3.at n=35A001993
- Number of triples (i,j,k) with 1 <= i < j < k <= n and gcd(i,j,k) = 1.at n=38A015616
- a(n) = Sum_{k=1..n} k*[ (n/k)*[ n/k ] ].at n=44A024932
- McKay-Thompson series of class 22a for Monster.at n=22A058569
- Expansion of series related to Liouville's Last Theorem: g.f. sum_{t>0} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^4 *product_{i=1..t} (1-x^i) ).at n=20A059821
- a(n) = 1^n + 6^n + 9^n.at n=4A074522
- Numerators of coefficients of asymptotic expansion of probability p(n) (see A002816) in powers of 1/n.at n=6A078630
- Sum of the first n primes whose indices are primes.at n=29A083186
- Convolution of Fibonacci(n-1) and 3^n.at n=8A106517
- Triangle read by rows T(n,k) = the number of Dyck paths of semilength n with k UUDDU's, 0<=k<=[(n-1)/2].at n=26A114848
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (1, -1, 0), (1, 0, 1), (1, 1, -1)}.at n=8A149006
- Number of planar triangular n X n X n nonnegative integer grids with every similarly oriented 3 X 3 X 3 subtriangle summing to 6.at n=10A154056
- Number of peakless Motzkin paths of length n, assuming that the (1,0)-steps come in 2 colors.at n=9A187256
- Number of lower triangles of an n X n 0..5 array with each element differing from all of its horizontal and vertical neighbors by one.at n=4A194995
- T(n,k)=Number of lower triangles of an n X n 0..k array with each element differing from all of its horizontal and vertical neighbors by one.at n=40A194998
- Number of lower triangles of a 5 X 5 0..n array with each element differing from all of its horizontal and vertical neighbors by one.at n=4A195001
- The number of tilings of an 8 X n floor with 1 X 4 tetrominoes.at n=14A236582
- Numbers k such that 1 + k + k^3 + k^5 + k^7 + k^9 + ... + k^49 is prime.at n=39A244388
- Triangular array: row n gives the coefficients of the polynomial p(n,x) defined in Comments.at n=31A247376
- Numbers n such that n + 15, n^2 + 15 and n^3 + 15 are prime.at n=51A253143