3081
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
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4480
- Proper Divisor Sum (Aliquot Sum)
- 1399
- 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
- 1872
- Möbius Function
- -1
- Radical
- 3081
- 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
- yes
- 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
- 154
- 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
- Doubly triangular numbers: a(n) = n*(n+1)*(n^2+n+2)/8.at n=12A002817
- Numbers that are the sum of 12 positive 10th powers.at n=3A004812
- Numbers that are the sum of at most 12 nonzero 10th powers.at n=45A004907
- Coefficients of period polynomials.at n=20A006308
- a(n) = p*(p-1)/2 for p = prime(n).at n=21A008837
- Second hexagonal numbers: a(n) = n*(2*n + 1).at n=39A014105
- Odd triangular numbers.at n=39A014493
- Numbers k that divide s(k), where s(1)=1, s(j)=9*s(j-1)+j.at n=22A014857
- Numbers k that divide s(k), where s(1)=1, s(j)=13*s(j-1)+j.at n=19A014861
- Integers k such that k divides 22^k - 1.at n=33A014959
- Binomial coefficients C(n,77).at n=2A017741
- Binomial coefficients C(79,n).at n=2A017795
- Sum of distinct prime divisors of prime(n)*prime(n-1) - 1.at n=28A023521
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=30A024834
- Sequence A025513 divided by 2.at n=35A025514
- Coordination sequence T1 for Zeolite Code ITE.at n=38A027369
- a(n) = binomial(n+2, 2) + binomial(n+4, 5).at n=11A027658
- 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 36.at n=18A031534
- a(n) = (2*n-1)*(4*n-1).at n=20A033567
- a(1) = 2; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=33A033679