225
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 9
- Divisor Sum
- 403
- Proper Divisor Sum (Aliquot Sum)
- 178
- 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
- 120
- Möbius Function
- 0
- Radical
- 15
- 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
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 52
- Smith 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
- no
- Odd
- yes
Names
- German
- zweihundertfünfundzwanzig· ordinal: zweihundertfünfundzwanzigste
- English
- two hundred twenty-five· ordinal: two hundred twenty-fifth
- Spanish
- doscientos veinticinco· ordinal: 225º
- French
- deux cent vingt-cinq· ordinal: deux cent vingt-cinqième
- Italian
- duecentoventicinque· ordinal: 225º
- Latin
- ducenti viginti quinque· ordinal: 225.
- Portuguese
- duzentos e vinte e cinco· ordinal: 225º
Appears in sequences
- Local stops on New York City 1 Train (Broadway-7 Avenue Local) subway.at n=25A000053
- a(n) = floor(n^(3/2)).at n=37A000093
- a(n) = floor(n^2/3).at n=26A000212
- Crossing number of complete graph with n nodes.at n=13A000241
- Number of permutations in the symmetric group S_n that have odd order.at n=6A000246
- Number of n-node rooted trees of height 4.at n=9A000299
- Unsigned Stirling numbers of first kind s(n,3).at n=3A000399
- n followed by n^2.at n=29A000463
- Sum of first n cubes; or n-th triangular number squared.at n=5A000537
- Octagonal numbers: n*(3*n-2). Also called star numbers.at n=9A000567
- Number of alkyls C_{n+15} H_{2n+10} (Anthr.) with n carbon atoms.at n=4A000648
- Powers of 15.at n=2A001024
- Partial sums of A001037, omitting A001037(1).at n=9A001036
- a(n+1) = n*a(n) + a(n-1) with a(0)=0, a(1)=1.at n=6A001040
- Generalized octagonal numbers: k*(3*k-2), k=0, +- 1, +- 2, +-3, ...at n=17A001082
- Numbers k such that k / (sum of digits of k) is a square.at n=19A001102
- a(n) is the solution to the postage stamp problem with n denominations and 3 stamps.at n=11A001213
- Squares of Bell numbers.at n=4A001247
- Squares of partition numbers.at n=7A001255
- Stirling numbers of first kind, s(n+3, n), negated.at n=2A001303