5557
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
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 5558
- 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
- 5556
- Möbius Function
- -1
- Radical
- 5557
- 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
- 129
- 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
- 733
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers that are the sum of 6 positive 6th powers.at n=39A003362
- Primes of the form m^2 + 3m + 9, where m can be positive or negative.at n=25A005471
- If x and y are terms, so is x*y + 9.at n=31A009350
- Primes that are palindromic in base 2 (but written here in base 10).at n=21A016041
- Primes whose digits are primes; primes having only {2, 3, 5, 7} as digits.at n=47A019546
- Numbers k such that the continued fraction for sqrt(k) has period 15.at n=27A020354
- Primes that contain digits 5 and 7 only.at n=5A020467
- Primes that remain prime through 3 iterations of function f(x) = 6x + 5.at n=42A023288
- a(n) = A027082(n, 2n-1).at n=9A027088
- Primes p whose digits do not appear in p^2.at n=49A030086
- 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 16.at n=4A031604
- Primes that are concatenations of n with n + 2.at n=8A032625
- Smallest n-digit prime containing only the digits 5 and 7, or 0 if no such prime exists.at n=3A036946
- Smallest prime containing exactly n 5's.at n=3A037063
- Numbers having three 5's in base 10.at n=21A043511
- a(n) = Sum_{i=0..n} A047080(i,n-i).at n=21A047084
- Smallest of three consecutive primes with a difference of 6: primes p such that p+6 and p+12 are the next two primes.at n=40A047948
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 21.at n=11A051962
- a(n) is the first prime p from A031924 such that A052180(primepi(p)) = prime(n).at n=16A052229
- Primes p whose period of reciprocal equals (p-1)/6.at n=35A056211