5421
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 7840
- Proper Divisor Sum (Aliquot Sum)
- 2419
- 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
- 3312
- Möbius Function
- -1
- Radical
- 5421
- Omega Function (Ω)
- 3
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 116
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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 continued fraction convergents to cube root of 7.at n=7A005485
- Sum of the numbers between the two n's in A026362.at n=38A026365
- Numbers k such that 131*2^k+1 is prime.at n=24A032415
- Number of partitions satisfying (cn(0,5) = 0 and cn(1,5) = cn(4,5)).at n=48A036818
- Positive numbers having the same set of digits in base 8 and base 10.at n=27A037442
- Sum of first n primes of form 4k+1.at n=32A038346
- Partial sums of primes congruent to 1 mod 6.at n=32A038349
- Number of partitions satisfying cn(2,5) <= cn(0,5) + cn(1,5) + cn(4,5) and cn(3,5) <= cn(0,5) + cn(1,5) + cn(4,5).at n=30A039871
- Numbers whose base-2 representation has exactly 11 runs.at n=34A043578
- a(1) = 7; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=41A046257
- Expansion of ( 1-x ) / ( 1-x-x^2-x^4+x^5 ).at n=19A052989
- Numbers k such that prime(k) + prime(k+1) is a square.at n=21A064397
- Dealing cards in a game of solitaire.at n=12A071761
- Triangle read by rows: the n-th row contains n numbers sorted in decreasing value, each build by dropping a different number from the sequence [n,n-1,n-2,....,1] and concatenating the n-1 others. By definition the first row contains 0.at n=12A081541
- Expansion of q / (chi(-q) * chi(-q^23)) in powers of q where chi() is a Ramanujan theta function.at n=53A092833
- Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and having k peaks of height >1 (n >= 1; 0 <= k <= n-1).at n=41A128747
- Least common multiple of 3 and n^2+n+1.at n=42A130723
- Numbers k such that prime(k) + prime(k+1) is a perfect power.at n=27A132746
- Sum of heights of all 1-watermelons with wall of length 2*n.at n=7A136439
- Numbers k such that (k!-6)/6 is prime.at n=19A139201