1829
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
- 4
- Divisor Sum
- 1920
- Proper Divisor Sum (Aliquot Sum)
- 91
- 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
- 1740
- Möbius Function
- 1
- Radical
- 1829
- 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
- 130
- 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
- Odd numbers not of form p + 2^k (de Polignac numbers).at n=40A006285
- Coordination sequence T3 for Zeolite Code BRE.at n=28A008060
- Coordination sequence T5 for Zeolite Code MFS.at n=27A008177
- Year of birth of n-th President of U.S.A.at n=20A008745
- a(n) = n*(2*n-3).at n=31A014107
- Numbers k such that the continued fraction for sqrt(k) has period 50.at n=4A020389
- a(n)-th nonsquarefree is sum of first k nonsquarefrees for some k.at n=26A020644
- Number of 3's in n-th term of A007651.at n=32A022468
- Place where n-th 1 occurs in A023123.at n=36A022785
- Number of 8's in all partitions of n.at n=31A024792
- a(n) = sum of the numbers between the two n's in A026276.at n=39A026279
- Number of partitions of n in which the least part is 7.at n=71A026800
- Number of partitions of n into distinct parts, the greatest being odd.at n=49A026837
- Number of partitions of n into distinct parts, the greatest being even.at n=49A026838
- a(n) = number of partitions of n into an odd number of parts, the least being 2; also a(n+2) = number of partitions of n into an even number of parts, each >=2.at n=39A027188
- Golc sequence in base 2. Left to right concatenation of n,int(log_2(n)),int(log_2(int(log_2(n)))),... in base 2.at n=27A028432
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 20 ones.at n=22A031788
- a(n) = (2*n+1) * (4*n-1).at n=15A033566
- Inverse Stolarsky array read by antidiagonals.at n=51A035507
- Numbers k such that d(i) is a power of 2 for all k <= i <= k+6, where d(i) = number of divisors of i.at n=30A036540