3557
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
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 3558
- 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
- 3556
- Möbius Function
- -1
- Radical
- 3557
- 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
- 149
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 498
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Rotatable partitions.at n=37A002722
- Primes of form n^2 + n + 17.at n=41A007635
- Primes of the form 2*k^2 + 29.at n=37A007641
- Coordination sequence T1 for Zeolite Code VET.at n=36A009902
- Coordination sequence T4 for Zeolite Code TER.at n=40A016436
- Primes whose digits are primes; primes having only {2, 3, 5, 7} as digits.at n=37A019546
- Numbers k such that the continued fraction for sqrt(k) has period 45.at n=8A020384
- Primes that remain prime through 2 iterations of the function f(x) = 2x + 7.at n=38A023244
- Sum of the numbers between the two n's in A026362.at n=31A026365
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 26 ones.at n=25A031794
- Primes of form x^2+77*y^2.at n=22A033249
- Numbers n such that string 5,7 occurs in the base 10 representation of n but not of n-1.at n=38A044389
- Numbers n such that string 5,7 occurs in the base 10 representation of n but not of n+1.at n=38A044770
- F-primes.at n=30A046872
- Primes at which difference pattern X2Y (X and Y >= 6) occurs in A001223.at n=44A047078
- Let (p1,p2), (p3,p4) be pairs of twin primes with p1*p2=p3+p4-1; sequence gives values of p1.at n=10A047976
- a(n) = T(2n-1,n), array T given by A048201.at n=30A048208
- a(n) = Sum_{i=0..floor(n/2)} T(2i,n-2i) where T is A049615.at n=44A049618
- Numbers n such that 145*2^n-1 is prime.at n=12A050598
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 9.at n=15A050958