79
domain: N
Properties
Digital Properties
- Digit Count
- 2
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 80
- 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
- 78
- Möbius Function
- -1
- Radical
- 79
- 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
- 35
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 22
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Names
- German
- neunundsiebzig· ordinal: neunundsiebzigste
- English
- seventy-nine· ordinal: seventy-ninth
- Spanish
- setenta y nueve· ordinal: 79º
- French
- soixante-dix-neuf· ordinal: soixante-dix-neufième
- Italian
- settantanove· ordinal: 79º
- Latin
- septuaginta novem· ordinal: 79.
- Portuguese
- setenta e nove· ordinal: 79º
Appears in sequences
- 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=37A000028
- Numbers that are not squares (or, the nonsquares).at n=70A000037
- 1-digit numbers arranged in alphabetical order, then the 2-digit numbers arranged in alphabetical order, then the 3-digit numbers, etc.at n=60A000052
- Local stops on New York City 1 Train (Broadway-7 Avenue Local) subway.at n=10A000053
- A Beatty sequence: a(n) = floor(n/(e-2)).at n=56A000062
- Odious numbers: numbers with an odd number of 1's in their binary expansion.at n=39A000069
- Central polygonal numbers (the Lazy Caterer's sequence): n(n+1)/2 + 1; or, maximal number of pieces formed when slicing a pancake with n cuts.at n=12A000124
- Lower Wythoff sequence (a Beatty sequence): a(n) = floor(n*phi), where phi = (1+sqrt(5))/2 = A001622.at n=48A000201
- a(8i+j) = 13i + a(j), where 1<=j<=8.at n=48A000202
- A Beatty sequence: floor(n*(e-1)).at n=45A000210
- 3*n - 2*floor(sqrt(4*n+5)) + 5.at n=32A000277
- Numbers that are the sum of 4 nonzero squares.at n=63A000414
- Primes and squares of primes.at n=25A000430
- The greedy sequence of integers which avoids 3-term geometric progressions.at n=57A000452
- Number of nonnegative solutions of x^2 + y^2 = z in first n shells.at n=38A000592
- n-th superior highly composite number A002201(n) is product of first n terms of this sequence.at n=36A000705
- Number of n-input 2-output switching networks under action of AG(n,2) on the inputs and complementing group C(2,2) on the outputs.at n=2A000850
- Numbers ending with a vowel in American English.at n=36A000861
- Numbers beginning with letter 's' in English.at n=23A000870
- Primes p of the form 3k+1 such that Sum_{x=1..p} cos(2*Pi*x^3/p) > sqrt(p).at n=5A000921