1225
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 9
- Divisor Sum
- 1767
- Proper Divisor Sum (Aliquot Sum)
- 542
- 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
- 840
- Möbius Function
- 0
- Radical
- 35
- Omega Function (Ω)
- 4
- 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
- yes
- Perfect Square
- yes
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- yes
- 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
- 132
- 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
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Hexagonal numbers: a(n) = n*(2*n-1).at n=25A000384
- n followed by n^2.at n=69A000463
- Number of discordant permutations.at n=3A000562
- Number of partitions of n in which no parts are multiples of 3.at n=30A000726
- Square triangular numbers: numbers that are both triangular and square.at n=3A001110
- Squares of tetrahedral numbers: a(n) = binomial(n+3,n)^2.at n=4A001249
- Perfect powers: m^k where m > 0 and k >= 2.at n=44A001597
- Successive denominators of Wallis's approximation to Pi/2 (reduced).at n=7A001902
- Coefficients of Legendre polynomials.at n=4A002462
- a(n) = n^2*(2*n^2 - 1); also Sum_{k=0..n-1} (2k+1)^3.at n=5A002593
- Squares and cubes.at n=42A002760
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals up to rotation and reflection.at n=27A003453
- Numbers of the form 5^i*7^j with i, j >= 0.at n=12A003595
- a(n) = n^2*(n+1)*(n+2)^2/6.at n=5A004256
- Binomial coefficient C(5n,n-8).at n=2A004350
- Number of alternating sign n X n matrices invariant under a quarter turn.at n=10A005160
- Erroneous version of A048798.at n=33A007914
- Product of divisors of n.at n=34A007955
- Number of non-Abelian metacyclic groups of order 2^n.at n=33A007982
- Coordination sequence T3 for Zeolite Code DDR.at n=22A008073