5541
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7392
- Proper Divisor Sum (Aliquot Sum)
- 1851
- 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
- 3692
- Möbius Function
- 1
- Radical
- 5541
- Omega Function (Ω)
- 2
- 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
- 67
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Denominators of approximations to e.at n=25A006259
- Numbers k such that the continued fraction for sqrt(k) has period 88.at n=6A020427
- a(n) = (d(n)-r(n))/5, where d = A026043 and r is the periodic sequence with fundamental period (0,2,3,0,0).at n=40A026045
- 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 48.at n=29A031546
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 34 ones.at n=34A031802
- Exactly 5 digits from {1,2,3,4,5,6,7,8,9} can precede a(n) to form a prime.at n=44A032695
- Number of nondividing sets on {1,2,...,n}.at n=31A051014
- Number of rooted trees with n nodes and 12 leaves.at n=4A055287
- McKay-Thompson series of class 30B for the Monster group with a(0) = 0.at n=30A058613
- The next smallest pair of numbers is taken so that a(2n-1)/a(2n) converges to e = exp(1).at n=39A065370
- a(n) = floor(Pi*n^2).at n=42A066643
- a(n) = floor(surface area of a sphere with radius n).at n=20A066644
- Numbers m such that [A070080(m), A070081(m), A070082(m)] is an acute scalene integer triangle with prime side lengths.at n=13A070123
- Numbers n such that both n^4 + 2 and n^4 - 2 are prime.at n=27A071351
- Number of iterations of the sine function to be less than 1/n with an initial argument of Pi/2 radians.at n=42A092906
- Indices of primes in sequence defined by A(0) = 43, A(n) = 10*A(n-1) - 7 for n > 0.at n=12A101720
- Denominators of "Farey fraction" approximations to e.at n=27A119015
- Irregular array where the n-th row are the divisors, not occurring earlier in the sequence, of the sum of the terms in all previous rows. a(1)=2.at n=48A120576
- a(n) = (7*n^2 - 17*n + 12)/2.at n=40A140065
- Number of planar triangular n X n X n nonnegative integer grids with every similarly oriented 5 X 5 X 5 subtriangle summing to 5.at n=9A154053