5454
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 12240
- Proper Divisor Sum (Aliquot Sum)
- 6786
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1800
- Möbius Function
- 0
- Radical
- 606
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 129
- 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
- Number of achiral trees with n nodes.at n=18A005629
- Expansion of 1/((1-x)*(1-2*x)*(1-x^2)).at n=11A011377
- a(n) = n*(15*n - 1)/2.at n=27A022272
- Number of partitions satisfying (cn(0,5) = 0 and cn(1,5) <= cn(2,5) and cn(1,5) <= cn(3,5) and cn(4,5) <= cn(2,5) and cn(4,5) <= cn(3,5)).at n=45A036812
- A variant of the recurrence for A001190.at n=19A038751
- a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 3, and a(3) = 2.at n=12A049969
- Numbers k such that (k + R(k)) / (k - R(k)) = +-11 where R(k) is the digit reversal of k (A004086).at n=6A062390
- Sum of terms in n-th row of A077164.at n=17A077167
- a(n) = 4a(n-1) + 3n with a(0) = 0.at n=6A078904
- Non-palindromic n and its digit reversal have the same sum of prime factors (with repetition).at n=20A085607
- Numbers k for which the quotient q(k)=(k+rev(k))/abs(k-rev(k)) is an integer.at n=7A087993
- For each pair of twin primes (p,p+2) take the absolute value of the difference between p and p with digits reversed.at n=50A088489
- a(n) is the least k such that k*(prime(n)#)^prime(n) - 1 is prime, where prime(n)# is the n-th primorial.at n=45A101047
- The sum of a triangular array made from a negative 6 fold permutation product with shifts up and down of {2,6}.at n=26A105162
- a(n) = (A112565(n) - 1)/n for n>=1.at n=7A112566
- Undulating Harshad numbers: numbers divisible by the sum of their own digits with decimal expansions in an abab...ab pattern.at n=37A129120
- Numbers m for which Sum_digits(m!) is a multiple of Sum_digits(m!!).at n=35A135206
- a[n] = number of bit strings of length n which have exactly as many substrings 000 as substrings 111.at n=15A158422
- a(n) = (7*n^2 + 7*n - 12)/2.at n=38A166146
- Number of n X 3 1..2 arrays containing at least one of each value, all equal values connected, rows considered as a single number in nondecreasing order, and columns considered as a single number in nonincreasing order.at n=29A166830