2539
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2540
- 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
- 2538
- Möbius Function
- -1
- Radical
- 2539
- 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
- 177
- 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
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 371
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Supersingular primes of the elliptic curve X_0 (11).at n=8A006962
- Primes of form 2n^2 - 2n + 19.at n=29A007639
- Number of permutations that are n-3 "block reversals" away from 12...n.at n=4A007974
- Coordination sequence T2 for Zeolite Code VNI.at n=31A009908
- a(n) = Sum_{k=1..n} ceiling(k^4/n).at n=9A014816
- Numbers k such that the continued fraction for sqrt(k) has period 78.at n=1A020417
- Expansion of Product_{m>=1} (1+q^m)^(-6).at n=12A022601
- Primes that remain prime through 2 iterations of function f(x) = 4x + 3.at n=35A023250
- Primes that remain prime through 2 iterations of function f(x) = 5x + 2.at n=31A023252
- Primes that remain prime through 2 iterations of function f(x) = 6x + 7.at n=36A023258
- Primes that remain prime through 2 iterations of function f(x) = 9x + 10.at n=44A023268
- Primes that remain prime through 3 iterations of function f(x) = 5x + 2.at n=7A023283
- Primes that remain prime through 3 iterations of function f(x) = 9x + 10.at n=15A023299
- Numbers that are the sum of 4 positive cubes in exactly 3 ways.at n=15A025405
- Numbers that are the sum of 4 positive cubes in 3 or more ways.at n=16A025407
- Sums of six consecutive squares: a(n) = n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2 + (n+5)^2.at n=18A027865
- Primes of the form n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2 + (n+5)^2.at n=6A027867
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 49.at n=10A031547
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 26 ones.at n=17A031794
- a(n) = prime(9*n-7).at n=41A031916