2739
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
- 5
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4032
- Proper Divisor Sum (Aliquot Sum)
- 1293
- 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
- 1640
- Möbius Function
- -1
- Radical
- 2739
- 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
- 40
- 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
- Number of partitions of 3n into n parts from the set {0, 1, ..., 6} (repetitions admissible).at n=17A001977
- a(n) = n*(5*n+1)/2.at n=33A005475
- Partial sums of fourth powers of Lucas numbers.at n=3A005972
- Coordination sequence T1 for Zeolite Code MEI.at n=38A008146
- Expansion of (1+x^8)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=57A008769
- Coordination sequence T2 for Zeolite Code VNI.at n=32A009908
- Expansion of Product_{m>=1} (1 - m*q^m)^5.at n=15A022665
- a(n) = dot_product(1,2,...,n)*(7,8,...,n,1,2,3,4,5,6).at n=15A026049
- Triangle T(n,m) = Sum_{k=0..m} Catalan(n-k)*Catalan(k).at n=41A028364
- Triangle read by rows: T(n,m) = Sum Catalan(n-k)*Catalan(k), k=0..m.at n=51A028376
- Concatenate rows of triangle in A028364 (removing duplicates).at n=34A028378
- An "extremely strange sequence": a(n+1) = [ A*a(n)+B ]/p^r, where p^r is the highest power of p dividing [ A*a(n)+B ] and p=2, A=4.001, B=1.2.at n=17A028948
- 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 51.at n=15A031549
- a(n)=(s(n)+3)/8, where s(n)=n-th base 8 palindrome that starts with 5.at n=40A043069
- Numbers n such that string 7,3 occurs in the base 9 representation of n but not of n-1.at n=36A044317
- Numbers n such that string 3,9 occurs in the base 10 representation of n but not of n-1.at n=30A044371
- Numbers n such that string 7,3 occurs in the base 9 representation of n but not of n+1.at n=36A044698
- Numbers n such that string 3,9 occurs in the base 10 representation of n but not of n+1.at n=30A044752
- Numbers n such that string 7,3 occurs in the base 10 representation of n but not of n+1.at n=29A044786
- Numbers whose base-5 representation contains exactly one 1 and three 4's.at n=31A045254