8978
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 32
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 13671
- Proper Divisor Sum (Aliquot Sum)
- 4693
- 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
- 4422
- Möbius Function
- 0
- Radical
- 134
- Omega Function (Ω)
- 3
- 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
- 91
- 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
- Numbers m such that phi(m) * sigma(m) + k^2 is not a square for any k.at n=30A015713
- 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 94.at n=10A031592
- Write 1,2,... in a clockwise spiral; sequence gives numbers on positive x axis.at n=47A033951
- Numbers that are not squarefree and whose Euler totient function is squarefree.at n=21A049198
- Write the numbers from 1 to n^2 in a spiraling square; a(n) is the total of the sums of the two diagonals.at n=19A059924
- Sum of digits = 8 times number of digits.at n=31A061425
- Least number k such that k has n anti-divisors.at n=32A066464
- If D[n] is divisor-set of n, then in set of 1+D only 2 primes occur:{2,3}; also n is not squarefree.at n=26A072607
- a(n) = 2^n + 7^n + 9^n.at n=4A074545
- Maximum number of regions into which the plane can be divided using n (concave) quadrilaterals.at n=34A077591
- a(n) = 2*prime(n)^2.at n=18A079704
- Twice a square but not the sum of 2 distinct squares.at n=41A081324
- Numbers k such that the numerator of Bernoulli(2k) is divisible by the square of 67, the third irregular prime.at n=9A093059
- Numbers k such that A109631(k) - A109631(k+1) = A109631(k+2).at n=10A109715
- Number of ordered rooted trees where each subtree from given node has the same number of nodes.at n=23A127525
- Indices of squares (of primes) in the semiprimes.at n=42A128301
- 2*p^2, for p an odd prime.at n=17A143928
- Eight bishops and one elephant on a 3 X 3 chessboard. G.f.: (1+x-5*x^2)/(1-3*x-x^2+6*x^3).at n=10A175655
- Numbers k such that there are only a finite nonzero number of sets of k consecutive triangular numbers that sum to a square.at n=42A176542
- a(n) = floor(1/{(n^4+2*n)^(1/4)}), where {}=fractional part.at n=66A184636