1523
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1524
- 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
- 1522
- Möbius Function
- -1
- Radical
- 1523
- 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
- 34
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 241
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of primes < prime(n)^2.at n=29A000879
- Numbers k such that phi(2k-1) < phi(2k), where phi is Euler's totient function A000010.at n=22A001836
- Numbers that are the sum of 4 positive 6th powers.at n=10A003360
- Dowling numbers: e.g.f.: exp(x + (exp(b*x) - 1)/b) with b=3.at n=5A003575
- Divisible only by primes congruent to 4 mod 7.at n=45A004622
- Numbers that are the sum of at most 4 nonzero 6th powers.at n=29A004855
- Numbers that are the sum of at most 5 nonzero 6th powers.at n=41A004856
- Mian-Chowla sequence (a B_2 sequence): a(1) = 1; for n>1, a(n) = smallest number > a(n-1) such that the pairwise sums of elements are all distinct.at n=31A005282
- Number of graphs on n nodes with 3 cliques.at n=12A005289
- Safe primes p: (p-1)/2 is also prime.at n=33A005385
- Primes of the form k^2 + k + 41.at n=38A005846
- Step at which n is expelled in Kimberling's puzzle (A035486).at n=42A006852
- Where the prime race among 5k+1, ..., 5k+4 changes leader.at n=13A007353
- Smallest prime > n^2.at n=38A007491
- Coordination sequence T2 for Zeolite Code AET.at n=27A008008
- Coordination sequence T1 for Zeolite Code EMT.at n=32A008086
- Coordination sequence T1 for Zeolite Code VFI.at n=30A008245
- Molien series for Weyl group E_8.at n=50A008582
- Expansion of (1+x^9)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=47A008770
- a(0) = 1, a(n) = n^2 + 2 for n > 0.at n=39A010000