73
domain: N
Properties
Digital Properties
- Digit Count
- 2
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 74
- 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
- 72
- Möbius Function
- -1
- Radical
- 73
- 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
- 115
- Smith Number
- no
Classification
- Natural
- yes
- Even
- no
- Odd
- yes
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
- 21
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Names
- German
- dreiundsiebzig· ordinal: dreiundsiebzigste
- English
- seventy-three· ordinal: seventy-third
- Spanish
- setenta y tres· ordinal: 73º
- French
- soixante-treize· ordinal: soixante-treizième
- Italian
- settantatre· ordinal: 73º
- Latin
- septuaginta tres· ordinal: 73.
- Portuguese
- setenta e três· ordinal: 73º
Appears in sequences
- Smallest prime power >= n.at n=71A000015
- The positive integers. Also called the natural numbers, the whole numbers or the counting numbers, but these terms are ambiguous.at n=72A000027
- Let k = p_1^e_1 p_2^e_2 p_3^e_3 ... be the prime factorization of n. Sequence gives k such that the sum of the numbers of 1's in the binary expansions of e_1, e_2, e_3, ... is odd.at n=35A000028
- Numbers that are not squares (or, the nonsquares).at n=64A000037
- 1-digit numbers arranged in alphabetical order, then the 2-digit numbers arranged in alphabetical order, then the 3-digit numbers, etc.at n=64A000052
- A Beatty sequence: a(n) = floor(n/(e-2)).at n=52A000062
- Odious numbers: numbers with an odd number of 1's in their binary expansion.at n=36A000069
- Number of partitions of n if there are two kinds of 1's and two kinds of 2's.at n=7A000097
- Number of partitions into non-integral powers.at n=6A000135
- Number of bicentered hydrocarbons with n atoms.at n=11A000200
- a(8i+j) = 13i + a(j), where 1<=j<=8.at n=44A000202
- A Beatty sequence: floor(n*(e-1)).at n=42A000210
- 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=4A000262
- Remove all factors of 2 from n; or largest odd divisor of n; or odd part of n.at n=72A000265
- 3*n - 2*floor(sqrt(4*n+5)) + 5.at n=30A000277
- Sums of three squares: numbers of the form x^2 + y^2 + z^2.at n=62A000378
- Numbers of form x^2 + y^2 + 2*z^2.at n=68A000401
- Numbers that are the sum of 2 nonzero squares.at n=25A000404
- Numbers that are the sum of three nonzero squares.at n=45A000408
- Numbers that are the sum of 4 nonzero squares.at n=57A000414