7748
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 14700
- Proper Divisor Sum (Aliquot Sum)
- 6952
- 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
- 3552
- Möbius Function
- 0
- Radical
- 3874
- Omega Function (Ω)
- 4
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A000201 (lower Wythoff sequence).at n=31A025118
- Expansion of (2 + x + x^2)/((1 - x)*(1 - x - x^2)).at n=15A026390
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 44.at n=3A031722
- Used by Polya in calculating A000598.at n=14A036677
- McKay-Thompson series of class 28D for Monster.at n=29A058609
- Engel expansion for tan(1).at n=5A084652
- Numbers k such that (k / sum of digits of k) and (k+1 / sum of digits of k+1) are both semiprime.at n=15A085774
- Integers i such that 16*i XOR 17*i = 33*i.at n=43A115833
- a(n) = n_{n^2}.at n=43A122625
- Number of facets of the Alternating Sign Matrix polytope ASM(n).at n=46A128445
- Retrograde trajectory of 11 under map n -> A132988(n).at n=38A132991
- Values of (n^5+47*n)/48 as n ranges over the numbers that are == +-1 mod 6.at n=4A151556
- a(n) = 16*n^2 + 4.at n=21A158444
- Number of n X n binary arrays with rows and columns, considered as binary numbers, in nondecreasing order, and all but the outermost row or column zero.at n=43A162024
- Number of slanted n X 4 (i=1..n) X (j=i..4+i-1) 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 3 neighbors with the same value.at n=5A165381
- Number of slanted 7Xn (i=1..7)X(j=i..n+i-1) 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 3 neighbors with the same value.at n=2A165399
- Numbers n such that there is at least one pair of twin primes 2^n - 2^k - 1 and 2^n - 2^k + 1 with n/2 <= k < n.at n=38A181408
- Generalized Fibonacci numbers A_{n,6}.at n=33A208092
- Number of (w,x,y) with all terms in {0,...,n} and w<x+y and x<y.at n=26A212980
- 16k^2-16k-4 interleaved with 16k^2+4 for k>=0.at n=45A216871