501
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 6
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 672
- Proper Divisor Sum (Aliquot Sum)
- 171
- 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
- 332
- Möbius Function
- 1
- Radical
- 501
- 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
- 110
- 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
- fünfhunderteins· ordinal: fünfhunderteinsste
- English
- five hundred one· ordinal: five hundred first
- Spanish
- quinientos uno· ordinal: 501º
- French
- cinq cent un· ordinal: cinq cent unième
- Italian
- cinquecentouno· ordinal: 501º
- Latin
- quingenti unus· ordinal: 501.
- Portuguese
- quinhentos e um· ordinal: 501º
Appears in sequences
- a(n) = 2^n - n - 2.at n=7A000247
- Number of "sets of lists": number of partitions of {1,...,n} into any number of lists, where a list means an ordered subset.at n=5A000262
- Numbers k such that 3^k, 3^(k+1) and 3^(k+2) have the same number of digits.at n=23A001682
- a(n) = 3 * prime(n).at n=38A001748
- Prime numbers of measurement.at n=21A002049
- a(n) = Sum_{d|n, d <= 4} d^2 + 4*Sum_{d|n, d>4} d.at n=63A002791
- Self numbers or Colombian numbers (numbers that are not of the form m + sum of digits of m for any m).at n=52A003052
- Numbers that are the sum of 6 positive 4th powers.at n=37A003340
- Numbers that are the sum of 11 positive 5th powers.at n=21A003356
- Roman numerals with 1 letter, in numerical order; then those with 2 letters, etc.at n=25A003587
- Roman numerals with 1 letter, in alphabetical order; then those with 2 letters, etc.at n=15A003588
- Add 4, then reverse digits; start with 0.at n=15A003608
- Add 4, then reverse digits; start with 0.at n=69A003608
- Odd numbers written backwards.at n=52A004156
- Triangular numbers written backwards.at n=14A004158
- Primes written in base 6.at n=41A004680
- Convolution of A002024 with itself.at n=24A004797
- Number of certain self-avoiding walks with n steps on square lattice (see reference for precise definition).at n=13A006143
- G.f.: Product_{k>=1} (1 + x^(2*k - 1)) / (1 - x^(2*k)).at n=26A006950
- Number of partitions of n into nonzero triangular numbers.at n=52A007294