663
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 1008
- Proper Divisor Sum (Aliquot Sum)
- 345
- 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
- 384
- Möbius Function
- -1
- Radical
- 663
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 25
- Smith Number
- yes
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- sechshundertdreiundsechzig· ordinal: sechshundertdreiundsechzigste
- English
- six hundred sixty-three· ordinal: six hundred sixty-third
- Spanish
- seiscientos sesenta y tres· ordinal: 663º
- French
- six cent soixante-trois· ordinal: six cent soixante-troisième
- Italian
- seicentosessantatre· ordinal: 663º
- Latin
- sescenti sexaginta tres· ordinal: 663.
- Portuguese
- seiscentos e sessenta e três· ordinal: 663º
Appears in sequences
- Expansion of x^3*(5-2*x)*(1-x^3)/(1-x)^4.at n=11A000338
- a(n) = 13*binomial(2n,n-6)/(n+7).at n=3A000590
- a(n) = a(n-2) + a(n-3) + a(n-4), with initial values a(0) = 0, a(1) = 2, a(2) = 3, a(3) = 6.at n=16A001634
- Numbers dividing A002037(i) and larger than A002037(i-1), for some i>0.at n=54A002038
- Numbers k such that 9*2^k + 1 is prime.at n=20A002256
- Odd squarefree numbers with an odd number of prime factors that have no prime factors greater than 31.at n=31A002556
- Divisors of 2^24 - 1.at n=31A003532
- Divisors of 2^48 - 1.at n=35A003553
- Numerators in expansion of (1-x)^{-1/4}.at n=5A004130
- a(n) = floor(n*phi^6), phi = golden ratio, A001622.at n=37A004921
- Numbers k such that k, k+1 and k+2 have the same number of divisors.at n=16A005238
- a(n) = n*(n+4)*(n+5)/6.at n=13A005586
- Number of 2-diregular connected digraphs with n nodes.at n=5A005642
- Number of Twopins positions.at n=14A005685
- Smith (or joke) numbers: composite numbers k such that sum of digits of k = sum of digits of prime factors of k (counted with multiplicity).at n=32A006753
- From fundamental unit of Z[ (-n)^{1/4} ].at n=30A006831
- Denominator of (2n+1)(2n+2) B_{2n}, where B_n are the Bernoulli numbers. Also denominators of the asymptotic expansion of the polygamma function psi'''(z).at n=25A006956
- Patterns in a dual ring.at n=9A007574
- Numbers k such that k*4^k + 1 is prime.at n=6A007646
- Number of maximal antichains in rooted plane trees on n nodes.at n=6A007853