5019
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
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 7680
- Proper Divisor Sum (Aliquot Sum)
- 2661
- 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
- 2856
- Möbius Function
- -1
- Radical
- 5019
- 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
- 64
- 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
- Numbers that are the sum of 7 positive 6th powers.at n=45A003363
- Numbers that are the sum of 12 positive 7th powers.at n=30A003379
- a(n) = n*(11*n^2 - 5)/6.at n=14A004467
- a(n) = floor( n*(n-1)*(n-2)/28 ).at n=53A011910
- a(n) = position of n^2 + (n+1)^2 + (n+2)^2 in A000408.at n=43A024802
- a(1)=1, a(n) = smallest odd number such that all sums of pairs of (not necessarily distinct) terms in the sequence are distinct.at n=38A034757
- T(n,n-3), array T as in A054106.at n=30A054107
- Numbers m such that there are precisely 3 groups of order m.at n=25A055561
- a(n) = Sum_{i=1..n} Sum_{j=1..i} (prime(i) - prime(j)).at n=19A062020
- Least m such that sqrt(m) has a period 2n continued fraction expansion whose palindrome part concatenates to a palindromic prime.at n=9A072135
- a(1) = 1; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=41A074336
- Sum of numbers that can be written as t*n + u*(n+1) for nonnegative integers t,u in exactly three ways.at n=5A076456
- Values of n corresponding to the terms in sequence A080155. For any k, the concatenation of the a(1) to a(k)-th primes is prime and each value of k is the smallest for which this is true.at n=44A080156
- G.f.: (1+3*x^3)/((1-x)^2*(1-x^3)^2).at n=39A092352
- a(2*k-1) = (2*k-1)^2 + 2 - k, a(2*k) = 6*k^2 + 2 - k: First column of the triangle A093915.at n=57A093916
- a(n) = n! - n(n-1)/2.at n=7A114311
- Number of permutations of length n which avoid the patterns 1243, 1342, 4312.at n=8A116770
- Start with 1015 and repeatedly reverse the digits and add 4 to get the next term.at n=2A117807
- Numbers ending in 1, 3, 7 or 9 such that either prepending or following them by one digit doesn't produce a prime.at n=24A124666
- Partial sums of A032598.at n=10A129330