5259
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7016
- Proper Divisor Sum (Aliquot Sum)
- 1757
- 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
- 3504
- Möbius Function
- 1
- Radical
- 5259
- 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
- 103
- 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
- Expansion of (1 + 2*x) / (1 - x - 4*x^2).at n=9A026581
- 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 71.at n=18A031569
- Lucky numbers with size of gaps equal to 18 (lower terms).at n=28A031900
- Lucky numbers that are decimal concatenations of n with n + 7.at n=5A032657
- Number of partitions satisfying cn(0,5) + cn(1,5) + cn(4,5) <= cn(2,5) + cn(3,5).at n=34A039878
- Numbers whose base-7 representation contains exactly four 2's.at n=3A043404
- Coordination sequence T4 for Zeolite Code MTF.at n=43A057307
- C(n+3)=2*C(n), where C(n) is Cototient(n) := n - phi(n) (A051953).at n=33A063480
- p[n_, k_]=Product[(E/(2-E))^i, {i, 1, n}]/Product[(E/(2-E))^i, {i, Floor[n/2^k], n}], a(n) = Sum[Floor[p[n, k]/(8*p[n-1, k])], {k, 1, 8}].at n=16A088663
- Smaller of two consecutive lucky numbers with the same digital sum.at n=18A118566
- Numbers k that divide 3^((k-1)/2) - 2^((k-1)/2) - 1.at n=38A130061
- Linear recurrence a(n) = a(n-3) + 2a(n-5), starting from all-one initial conditions.at n=35A133683
- a(n) = least positive integer k such that k^2+3 is divisible by at least n distinct primes.at n=6A138769
- a(n) = n^3 + 73*n^2 + n + 67.at n=8A163303
- Index k of the semiprime A001358(k) = prime(n) * prime(n+1).at n=33A172348
- Number of rooted trees with n nodes and omega-valency 5.at n=14A193490
- Triangle of coefficients of polynomials v(n,x) jointly generated with A208763; see the Formula section.at n=54A208764
- Triangle of coefficients of polynomials v(n,x) jointly generated with A208915; see the Formula section.at n=54A208916
- Number of (n+1) X (3+1) 0..1 arrays with every 2 X 2 subblock antidiagonal maximum minus diagonal minimum nondecreasing horizontally and diagonal maximum minus antidiagonal minimum nondecreasing vertically.at n=25A253392
- G.f.: 1/((1-t^8)*(1-t)*(1-t^3)*(1-t^5)*(1-t^7)*(1-t^9)*(1-t^11)*(1-t^13)*(1-t^15)).at n=54A266748