7928
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
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14880
- 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
- 3960
- Möbius Function
- 0
- Radical
- 1982
- Omega Function (Ω)
- 4
- 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
- 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
- Average theta series of odd unimodular lattices in dimension 12.at n=4A029751
- Numbers k such that 121*2^k+1 is prime.at n=11A032410
- Number of centered 5-valent trees with n nodes.at n=16A036648
- Number of partitions of n such that cn(0,5) = cn(2,5) < cn(1,5) < cn(3,5) = cn(4,5).at n=74A036860
- Number of partitions satisfying cn(0,5) <= cn(1,5) + cn(2,5) + cn(3,5) and cn(0,5) <= cn(4,5) + cn(2,5) + cn(3,5).at n=32A039845
- Number of 4 X n nonnegative integer matrices with all column sums 3, up to row and column permutation.at n=6A058409
- Engel expansion of Sum_{k>=0} 1/(9 + k)^k.at n=10A063192
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 87 ).at n=38A063360
- Least k for the Theodorus spiral to complete n revolutions.at n=27A072895
- Number of numbers that are ternary squarefree words of length n.at n=26A088953
- a(n) = Sum_{i=1..n} A005235(i).at n=45A097589
- Even numbers n such that n^2 is an arithmetic number.at n=32A107924
- Indices of Fibonacci numbers in A073656, i.e., A073656(n) = F(a(n)).at n=17A119755
- Numbers k such that there is a number m < k satisfying A000203(k) = A000203(m) = m + k - gcd(m,k).at n=20A124141
- Concatenation of first two digits and last two digits of n-th even perfect number.at n=39A138875
- Number of ways to place 4 nonattacking knights on a 4 X n board.at n=6A172213
- Number of nonempty subsets of {1, 2, ..., n} with <= 4 pairwise coprime elements.at n=32A187265
- Number of partitions of n into terms of (1,3)-Ulam sequence, cf. A002859.at n=49A199118
- Triangle of coefficients of polynomials u(n,x) jointly generated with A208920; see the Formula section.at n=42A208919
- Number of 2 X 2 matrices having all elements in {-n,...n} and determinant 5.at n=25A209990