8381
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
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 9210
- Proper Divisor Sum (Aliquot Sum)
- 829
- 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
- 7616
- Möbius Function
- 0
- Radical
- 493
- Omega Function (Ω)
- 3
- 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
- 109
- 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
- no
- Odd
- yes
Appears in sequences
- a(0) = 1, a(n) = 19*n^2 + 2 for n>0.at n=21A010009
- a(n) = (2*n - 5)n^2.at n=17A015240
- Numbers k such that the continued fraction for sqrt(k) has period 15.at n=38A020354
- a(n) = (d(n)-r(n))/5, where d = A026063 and r is the periodic sequence with fundamental period (1,4,0,0,0).at n=52A026065
- Sum of the next n members of the list of twin primes.at n=10A038345
- Number of partitions satisfying cn(2,5) + cn(3,5) <= cn(0,5).at n=41A039861
- Number of terms (excluding the first) of A002211 for which the geometric mean produces progressively better approximations to Khinchin's constant (itself).at n=23A048613
- Numerators of row 4 of table described in A051714/A051715.at n=33A051722
- Numbers k > 1 such that, in base 4, k and k^2 contain the same digits in the same proportion.at n=23A061658
- Triangle read by rows, in which n-th row contains smallest set of n consecutive numbers with distinct prime signatures.at n=51A083788
- a(n) = n^3 - 2*n^2 + 2.at n=20A100109
- Odd numbers n such that there exists a solution to lcm(s,z-s) = n, lcm(t,z-t) = n-2 and 0 < s+t < z < n.at n=29A108157
- Numbers whose anti-divisors sum to a perfect cube.at n=17A109351
- Sum of n and partition number of n.at n=32A133041
- Totally multiplicative sequence with a(p) = 6p-1 for prime p.at n=44A166655
- Numbers a(n) for which there exists k>1 such that the number of partitions of a(n) into k parts is k.at n=31A209122
- Products of 3 evil primes (A027699) p,q,r, such that numbers p*q, p*r, q*r, and p*q*r are odious (A000069).at n=7A230353
- Where records occur in A239656 (the first differences of sphenic numbers).at n=6A239674
- Number of partitions of n with difference 3 between the number of odd parts and the number of even parts, both counted without multiplicity.at n=37A242694
- a(n) = 29*n^2.at n=17A244635