5209
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 5210
- 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
- 5208
- Möbius Function
- -1
- Radical
- 5209
- 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
- 41
- 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
- 693
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = round(1000*log_2(n)).at n=36A004266
- Primes whose reversal is a square.at n=9A007488
- 3 and -3 are both 4th powers (one implies other) mod these primes p=1 mod 8.at n=36A014755
- Primes that remain prime through 2 iterations of the function f(x) = 3*x + 2.at n=45A023246
- Primes that remain prime through 2 iterations of function f(x) = 8x + 9.at n=38A023264
- Primes that remain prime through 3 iterations of function f(x) = 6x + 5.at n=41A023288
- Primes that remain prime through 4 iterations of function f(x) = 6x + 5.at n=12A023317
- Numbers whose least quadratic nonresidue (A020649) is 11.at n=32A025024
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 28.at n=0A031616
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 38 ones.at n=20A031806
- Lower prime of a difference of 18 between consecutive primes.at n=19A031936
- Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 2,1,1.at n=4A037556
- Primes with first digit 5.at n=40A045711
- Triangle read by rows. Same rule as Aitken triangle (A011971) except T(0,0) = 1, T(1,0) = 2.at n=34A046937
- Sequence formed from rows of triangle A046937.at n=28A046938
- Primes p such that pp'-2 is prime, where p' denotes the next prime after p.at n=29A048797
- First spoke of a hexagonal spiral.at n=42A056105
- Primes p such that x^31 = 2 has no solution mod p.at n=19A059225
- Primes p such that p^7 reversed is also prime.at n=34A059700
- Primes with 17 as smallest positive primitive root.at n=7A061329