481
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 532
- Proper Divisor Sum (Aliquot Sum)
- 51
- 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
- 432
- Möbius Function
- 1
- Radical
- 481
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 48
- Smith 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
Names
- German
- vierhunderteinundachtzig· ordinal: vierhunderteinundachtzigste
- English
- four hundred eighty-one· ordinal: four hundred eighty-first
- Spanish
- cuatrocientos ochenta y uno· ordinal: 481º
- French
- quatre cent quatre-vingt-un· ordinal: quatre cent quatre-vingt-unième
- Italian
- quattrocentoottantuno· ordinal: 481º
- Latin
- quadringenti octoginta unus· ordinal: 481.
- Portuguese
- quatrocentos e oitenta e um· ordinal: 481º
Appears in sequences
- Number of partitions into non-integral powers.at n=13A000148
- a(n) = floor(n^2/3).at n=38A000212
- Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); A000099 gives values of n where |P(n)| sets a new record; sequence gives A(A000099(n)).at n=10A000323
- Octagonal numbers: n*(3*n-2). Also called star numbers.at n=13A000567
- Generating function = Product_{m>=1} 1/(1 - x^m)^2; a(n) = number of partitions of n into parts of 2 kinds.at n=10A000712
- Deceptive nonprimes: composite numbers k that divide the repunit R_{k-1}.at n=3A000864
- Flavius Josephus's sieve: Start with the natural numbers; at the k-th sieving step, remove every (k+1)-st term of the sequence remaining after the (k-1)-st sieving step; iterate.at n=24A000960
- a(n) = ceiling(n^2/2).at n=31A000982
- "Half-Catalan numbers": a(n) = Sum_{k=1..floor(n/2)} a(k)*a(n-k) with a(1) = 1.at n=11A000992
- Numbers k such that sum of squares of k consecutive integers >= 1 is a square.at n=53A001032
- Numbers n such that the sum of the squares of n consecutive positive odd numbers x^2 + (x+2)^2 + ... + (x+2n-2)^2 = k^2 for some integer k. The least values of x and k for each n are in A056131 and A056132, respectively.at n=32A001033
- Generalized octagonal numbers: k*(3*k-2), k=0, +- 1, +- 2, +-3, ...at n=25A001082
- Moran numbers: k such that k/(sum of digits of k) is prime.at n=36A001101
- Centered square numbers: a(n) = 2*n*(n+1)+1. Sums of two consecutive squares. Also, consider all Pythagorean triples (X, Y, Z=Y+1) ordered by increasing Z; then sequence gives Z values.at n=15A001844
- Expansion of (psi(-x) / phi(-x))^5 in powers of x where phi(), psi() are Ramanujan theta functions.at n=5A001939
- Numbers k for which the rank of the elliptic curve y^2 = x^3 + k is 2.at n=70A002155
- Let p = A007645(n) be the n-th generalized cuban prime and write p^2 = x^2 + 3*y^2 with y > 0; a(n) = x.at n=43A002367
- Let p = A007645(n) be the n-th generalized cuban prime and write p^2 = x^2 + 3*y^2 with y > 0; a(n) = x.at n=49A002367
- A generalized partition function.at n=9A002602
- Number of permutations of length n with two 3-sequences.at n=7A002630