2925
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 5642
- Proper Divisor Sum (Aliquot Sum)
- 2717
- 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
- 1440
- Möbius Function
- 0
- Radical
- 195
- Omega Function (Ω)
- 5
- 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
- yes
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 141
- 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
- Tetrahedral (or triangular pyramidal) numbers: a(n) = C(n+2,3) = n*(n+1)*(n+2)/6.at n=25A000292
- Numbers that are the sum of 2 squares in exactly 3 ways.at n=31A000443
- a(n) = 1^2 + 3^2 + 5^2 + 7^2 + ... + (2*n-1)^2 = n*(4*n^2 - 1)/3.at n=13A000447
- Binomial coefficient C(3n,n-6).at n=3A004324
- Expansion of (1-x+x^2)/((1-x)^2*(1-x^2)*(1-x^4)).at n=49A005232
- Mian-Chowla sequence (a B_2 sequence): a(1) = 1; for n>1, a(n) = smallest number > a(n-1) such that the pairwise sums of elements are all distinct.at n=40A005282
- a(n) = n*(n^2 + 1)/2.at n=18A006003
- Dodecahedral numbers: a(n) = n*(3*n - 1)*(3*n - 2)/2.at n=9A006566
- Coordination sequence T2 for Zeolite Code AFR.at n=41A008020
- Expansion of 1/((1-x)^2*(1-x^2)*(1-x^4)).at n=48A008804
- Binomial coefficient C(27,n).at n=3A010943
- Binomial coefficient C(27,n).at n=24A010943
- a(n) = binomial coefficient C(n,24).at n=3A010977
- a(n) = n*(2*n-3).at n=39A014107
- Odd tetrahedral numbers: a(n) = (4*n+1)*(4*n+2)*(4*n+3)/6.at n=6A015219
- Numbers whose base-2 representation is the juxtaposition of two identical strings.at n=44A020330
- Numbers whose base-4 representation is the juxtaposition of two identical strings.at n=44A020332
- Numbers whose base-8 representation is the juxtaposition of two identical strings.at n=44A020336
- Binomial coefficients: C(n,k), 3 <= k <= n-3, sorted, duplicates removed.at n=38A024755
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+4)/m < s for some integer k.at n=17A024848