5528
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10380
- Proper Divisor Sum (Aliquot Sum)
- 4852
- 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
- 2760
- Möbius Function
- 0
- Radical
- 1382
- 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
- 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
- Numbers k such that Fib(k) == 21 (mod k).at n=36A023179
- 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 17.at n=40A031515
- Numbers k such that 241*2^k+1 is prime.at n=3A032497
- First gap of n in sequence A038593 (upper terms).at n=38A038662
- Numbers ending with '8' that are the difference of two positive cubes.at n=23A038863
- Numbers k such that x^k + x^4 + 2 is irreducible over GF(3).at n=23A058237
- Type D Eulerian triangle.at n=37A066094
- Type D Eulerian triangle.at n=43A066094
- Natural numbers of the form p^3 - q^3, where p and q are primes.at n=25A086120
- Least k such that 10^n + k - 1 is the first of a pair of twin primes.at n=22A103129
- Row 3 of array in A114999.at n=48A115007
- Sums of rows of the triangle in A116366.at n=29A116367
- Numbers for which the sum of the digits is the square root of the product of their digits.at n=12A117720
- Numbers n such that the numerator of BernoulliB[n] is divisible by 691.at n=19A119864
- a(0)=3; a(n) = n^2 + a(n-1) for n>0.at n=25A153057
- a(n) = smallest number m such that m^2 and n^2 share no common digits and m^2 and n^2 together use all 10 digits, a(n) = 0 if no such m exists.at n=35A158931
- Conjecturally, even numbers n such that every even number greater than n has more decompositions as the sum of two primes.at n=35A174327
- A185243(n) is the a(n)-th triangular number.at n=35A185257
- a(n) = Sum_{i=0..n} digsum_6(i)^4, where digsum_6(i) = A053827(i).at n=16A231675
- Number of partitions p of n such that (maximal multiplicity over the parts of p) = (number of numbers in p having multiplicity > 1).at n=42A241132