2500
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 7
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 15
- Divisor Sum
- 5467
- Proper Divisor Sum (Aliquot Sum)
- 2967
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1000
- Möbius Function
- 0
- Radical
- 10
- Omega Function (Ω)
- 6
- 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
- yes
- 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
- 27
- 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
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- yes
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Tetranacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4) with a(0) = a(1) = a(2) = a(3) = 1.at n=14A000288
- Numbers that are the sum of 2 squares in exactly 3 ways.at n=22A000443
- Number of one-sided polyominoes with n cells.at n=9A000988
- a(n) = Product_{k=1..n} k^(2k - 1 - n).at n=5A001142
- a(n) = sigma_2(n): sum of squares of divisors of n.at n=41A001157
- Numbers of the form 2^i*5^j with i, j >= 0.at n=35A003592
- a(0) = 1; a(n) = 4*5^(n-1) for n >= 1.at n=5A005054
- Number of paraffins.at n=17A006001
- 4-dimensional analog of centered polygonal numbers. Also number of regions created by sides and diagonals of a convex n-gon in general position.at n=17A006522
- Number of regions in regular n-gon with all diagonals drawn.at n=16A007678
- Product of the proper divisors of n.at n=49A007956
- a(n) = floor(n/5)*floor((n+1)/5)*floor((n+2)/5)*floor((n+3)/5)*floor((n+4)/5).at n=24A008382
- Expansion of (1+x)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=52A008762
- Triangle of coefficients in expansion of (1+5x)^n.at n=24A013612
- Numbers that are not the sum of a square and a prime.at n=42A014090
- a(n) = (F(n+1) + L(n))^2 where F(n) are the Fibonacci numbers (A000045) and L(n) are the Lucas numbers (A000032).at n=7A014717
- Squares of even hexagonal pyramidal numbers.at n=1A014803
- a(n+1) = floor(a(n)/2) * ceiling(a(n)/2), a(0) = 5.at n=5A014980
- a(0)=1, a(1)=7, a(n) = sum_{k=0}^{k=n-1} 7^k a(k).at n=3A015495
- Expansion of 1 / ((1-x) * (1-3*x) * (1-12*x)).at n=3A016217