7138
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
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 11088
- 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
- 3444
- Möbius Function
- -1
- Radical
- 7138
- 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
- 75
- 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
- Coordination sequence for MgNi2, Position Ni2.at n=21A009932
- Coordination sequence for alpha-Mn, Position Mn1.at n=22A009950
- Minimal number of people to give a 50% probability of having at least n coincident birthdays in one year.at n=33A014088
- Expansion of 1/(1-x^5-x^6-x^7-x^8-x^9-x^10).at n=43A017841
- Magic numbers: atoms with full shells containing any of these numbers of electrons are considered electronically stable.at n=32A018227
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Lucas numbers), t = A014306.at n=33A025097
- 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 84.at n=7A031582
- Numbers whose set of base-13 digits is {1,3}.at n=28A032920
- Expansion of (1-x)/(1-3x-4x^2+4x^3).at n=7A052965
- Numbers k>11 such that x^k + x^11 + x^10 + x^9 + x^8 + x^7 + x^6 + x^5 + x^4 + x^3 + x^2 + x + 1 is irreducible over GF(2).at n=34A057488
- Number of subsets of {1, ..., n} with no four terms in arithmetic progression.at n=14A066369
- Vertical of triangular spiral in A051682.at n=39A081271
- Quotient of LCM of prime(n+1)-1 and prime(n)-1 and GCD of the same two numbers.at n=38A083555
- Number of lattice points on or inside the rectangle formed by [1 <= x <= (q-1)/2] and [1 <= y <= (p-1)/2], where p = n-th prime, q = (n-1)-st prime.at n=37A087427
- 0*9, 1*8, 2*7, 3*6, 4*5; 10*19, 11*18, ..., 14*15; 20*29, 21*28, ..., 24*25; 30*39, ...at n=43A096229
- Number of squares on infinite half chessboard at <=n knight moves from a fixed point on the edge.at n=32A098498
- Numbers k such that the numerator of the Bernoulli number B(2k) ends with the digits 691.at n=25A132184
- Number of 2 X 2 singular integer matrices with entries from {2,...,n}.at n=42A134978
- Integers of the form sum_{i=2521..j} i/(i-2520) for any upper limit j.at n=8A144971
- 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, -1, 1), (0, 1, 1), (1, 0, 1), (1, 1, -1)}.at n=7A150274