1489
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1490
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 1488
- Möbius Function
- -1
- Radical
- 1489
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- no
- Narcissistic Number
- no
- Collatz Steps
- 47
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 237
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- 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=17A000323
- Primes p of the form 3k+1 such that -sqrt(p) < sum_{x=1..p} cos(2*Pi*x^3/p) < sqrt(p).at n=35A000922
- Number of graphical basis partitions of 2n.at n=20A001130
- Number of partitions of n into Fibonacci parts (with a single type of 1).at n=40A003107
- a(n) is the number of integers m which take n steps to reach 1 in '3x+1' problem.at n=33A005186
- Centered triangular numbers: a(n) = 3*n*(n-1)/2 + 1.at n=31A005448
- Primes of the form m^2 + 3m + 9, where m can be positive or negative.at n=16A005471
- Cald's sequence: a(n+1) = a(n) - prime(n) if that value is positive and new, otherwise a(n) + prime(n) if new, otherwise 0; start with a(1)=1.at n=109A006509
- Greater of twin primes.at n=49A006512
- Discriminants of totally real cubic fields.at n=42A006832
- Smallest odd number expressible in at least n ways as p+2*m^2 where p is 1 or a prime and m >= 0.at n=20A007697
- Coordination sequence for Paracelsian.at n=26A008260
- Expansion of 1/((1-x)*(1-x^3)*(1-x^5)*(1-x^7)*(1-x^9)).at n=64A008674
- a(n) = floor( n*(n-1)*(n-2)*(n-3)/22 ).at n=15A011932
- Numbers k such that the continued fraction for sqrt(k) has period 21.at n=11A020360
- Primes p such that 7*p + 4 is also prime.at n=43A023224
- Primes p such that 10*p + 1 is also prime.at n=50A023237
- Primes that remain prime through 2 iterations of function f(x) = 6x + 7.at n=27A023258
- Primes that remain prime through 2 iterations of function f(x) = 7x + 6.at n=20A023259
- Primes that remain prime through 2 iterations of function f(x) = 9x + 10.at n=33A023268