2459
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2460
- 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
- 2458
- Möbius Function
- -1
- Radical
- 2459
- 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
- 102
- 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
- yes
- Safe Prime
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 364
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p == 7, 19, 23 (mod 40) such that (p-1)/2 is also prime.at n=21A000353
- Lucasian primes: p == 3 (mod 4) with 2*p+1 prime.at n=37A002515
- a(n) = floor(n*phi^10), where phi is the golden ratio, A001622.at n=20A004925
- Safe primes p: (p-1)/2 is also prime.at n=43A005385
- Prime self (or Colombian) numbers: primes not expressible as the sum of an integer and its digit sum.at n=36A006378
- Primes of form 3*k^2 - 3*k + 23.at n=25A007637
- Numbers n such that n, 2n+1, and 4n+3 all prime.at n=20A007700
- Coordination sequence T2 for Zeolite Code MOR.at n=32A008183
- Coordination sequence T1 for Zeolite Code NON.at n=30A008212
- n-th prime p(k) such that p(k) + p(k+9) = p(k+3) + p(k+6).at n=29A022893
- Primes that remain prime through 2 iterations of function f(x) = 4x + 3.at n=34A023250
- Primes that remain prime through 2 iterations of function f(x) = 8x + 9.at n=22A023264
- Numbers that are the sum of 4 positive cubes in exactly 3 ways.at n=12A025405
- Numbers that are the sum of 4 positive cubes in 3 or more ways.at n=13A025407
- Coordination sequence T4 for Zeolite Code ITE.at n=34A027372
- a(n) = n^2 + n + 9.at n=49A027694
- Primes of the form k^2 + k + 9.at n=8A027758
- Primes with property that when squared all even digits occur together and all odd digits occur together.at n=25A030480
- 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=5A031547
- a(n) = prime(9*n - 5).at n=40A031909