1663
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
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1664
- 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
- 1662
- Möbius Function
- -1
- Radical
- 1663
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 73
- 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
- 261
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p of the form 3k+1 such that sum_{x=1..p} cos(2*Pi*x^3/p) < -sqrt(p).at n=23A000923
- Number of partitions of n into parts 2, 3, 4, 5, 6, 7.at n=50A001996
- a(n) = 1000*log_10(n) rounded to the nearest integer.at n=45A004226
- Numbers k such that k-6, k, and k+6 are primes.at n=42A006489
- Prime triples: p; p+2 or p+4; p+6 all prime.at n=42A007529
- Numbers k such that (3^k + 1)/4 is prime.at n=11A007658
- Number of partitions of n in which no part occurs just once.at n=41A007690
- Coordination sequence T1 for Zeolite Code AFR.at n=31A008019
- Coordination sequence T5 for Zeolite Code BOG.at n=29A008053
- Numbers k such that the continued fraction for sqrt(k) has period 48.at n=5A020387
- Initial members of prime triples (p, p+4, p+6).at n=20A022005
- n-th prime p(k) such that p(k) + p(k+4) = p(k+1) + p(k+3).at n=48A022887
- Primes p such that 4*p+1 is also prime.at n=48A023212
- Primes p such that 4*p + 7 is also prime.at n=48A023215
- Primes that remain prime through 2 iterations of function f(x) = 2x + 3.at n=33A023242
- Primes p such that 3*p + 4 and 9*p + 16 are also prime.at n=26A023247
- Primes that remain prime through 3 iterations of function f(x) = 3x + 4.at n=2A023278
- Numbers with exactly 9 ones in binary expansion.at n=19A023691
- a(n) = [ (2nd elementary symmetric function of P(n))/(first elementary symmetric function of P(n)) ], where P(n) = {first n+1 primes}.at n=40A024452
- a(n) = floor(2nd elementary symmetric function of Sum_{j=1..k} 1/j, k = 1,2,...,n).at n=19A025212