7749
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 13440
- Proper Divisor Sum (Aliquot Sum)
- 5691
- 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
- 4320
- Möbius Function
- 0
- Radical
- 861
- Omega Function (Ω)
- 5
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 52
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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 n-step mappings with 4 inputs.at n=14A005945
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite RTE = RUB-3 [Si24O48].2R starting with a T3 atom.at n=12A019223
- 9 times the triangular numbers A000217.at n=41A027468
- a(n) = (2*n+1) * (4*n-1).at n=31A033566
- Minimum area rectangle into which squares of sizes 1, 2, 3, ... n can be packed.at n=27A038666
- Numbers whose base-5 representation contains exactly two 2's and three 4's.at n=29A045288
- 24-gonal numbers: a(n) = n*(11*n-10).at n=27A051876
- Numbers k such that prime(k) + prime(k+1)*2 is a square.at n=16A064504
- (Sum of digits of n)^5 - (sum of digits of n^5).at n=6A069979
- Numbers k such that phi(m) = 96*k+2 has no solution.at n=4A071624
- Numbers k such that gcd(k, reverse(k)) = 27 = 3^3, where reverse(x) = A004086(x).at n=22A072016
- a(1) = 4; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=40A074341
- Numbers k that divide A005554(k) (the sum of consecutive Motzkin numbers).at n=31A081741
- Numbers k such that the product of Euler phi of the 2 consecutive integers {k,k+1} is a 4th power: if sqrt(sqrt(phi(k)*phi(k+1))) is an integer, then k is here.at n=6A082788
- a(n) = (n^3 + 24*n^2 + 65*n + 36)/6.at n=29A087863
- Triangle read by rows: T(n, k) = 10^(n-1) - 1 + k*floor(9*10^(n-1)/n), for 1 <= k <= n.at n=8A093846
- Number of upper Wythoff primes (A095281) in range ]2^n,2^(n+1)].at n=17A095291
- Number of partitions of n such that all parts, with the possible exception of the smallest, appear only once.at n=42A115029
- Pairs (j, k) of numbers j<k such that phi(j) = phi(k), sigma(j) = sigma(k), d(j) = d(k).at n=24A134922
- 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, 0), (-1, 0, 0), (0, 1, 1), (1, -1, 1), (1, 0, -1)}.at n=8A149032