551
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 600
- Proper Divisor Sum (Aliquot Sum)
- 49
- 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
- 504
- Möbius Function
- 1
- Radical
- 551
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 43
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- fünfhunderteinundfünfzig· ordinal: fünfhunderteinundfünfzigste
- English
- five hundred fifty-one· ordinal: five hundred fifty-first
- Spanish
- quinientos cincuenta y uno· ordinal: 551º
- French
- cinq cent cinquante et un· ordinal: cinq cent cinquante et unième
- Italian
- cinquecentocinquantuno· ordinal: 551º
- Latin
- quingenti quinquaginta unus· ordinal: 551.
- Portuguese
- quinhentos e cinquenta e um· ordinal: 551º
Appears in sequences
- Number of trees with n unlabeled nodes.at n=12A000055
- Number of n-node steric rooted ternary trees; number of n carbon alkyl radicals C(n)H(2n+1) taking stereoisomers into account.at n=9A000625
- Number of bicentered 3-valent (or boron, or binary) trees with n nodes.at n=15A000673
- Generalized pentagonal numbers: m*(3*m - 1)/2, m = 0, +-1, +-2, +-3, ....at n=38A001318
- Number of partitions of n into at most 4 parts.at n=38A001400
- Partial sums of A001462; also a(n) is the last occurrence of n in A001462.at n=58A001463
- Expansion of g.f. x/((1 - x)^2*(1 - x^3)).at n=56A001840
- MacMahon's generalized sum of divisors function.at n=9A002128
- Numbers y such that p^2 = x^2 + y^2, 0 < x < y, p = A002144(n).at n=51A002365
- Squares written in base 8.at n=18A002441
- Odd squarefree numbers with an even number of prime factors that have no prime factors greater than 31.at n=41A002557
- Number of partitions of n into parts 5k+2 or 5k+3.at n=48A003106
- Numbers that are the sum of 5 positive 5th powers.at n=13A003350
- a(n) = 5*a(n-1) - a(n-2) for n > 1, a(0) = 0, a(1) = 1.at n=5A004254
- Divisible only by primes congruent to 4 mod 5.at n=26A004618
- Primes written in base 6.at n=46A004680
- Numbers that are the sum of at most 5 positive 5th powers.at n=44A004845
- a(n) = floor(n*phi^7), where phi is the golden ratio, A001622.at n=19A004922
- Second pentagonal numbers: a(n) = n*(3*n + 1)/2.at n=19A005449
- Positions of remoteness 5 in Beans-Don't-Talk.at n=27A005697