29
domain: N
Properties
Digital Properties
- Digit Count
- 2
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 30
- 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
- 28
- Möbius Function
- -1
- Radical
- 29
- 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
- yes
- Tetrahedral Number
- no
- Pell Number
- yes
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 18
- 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
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 10
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Names
- German
- neunundzwanzig· ordinal: neunundzwanzigste
- English
- twenty-nine· ordinal: twenty-ninth
- Spanish
- veintinueve· ordinal: 29º
- French
- vingt-neuf· ordinal: vingt-neufième
- Italian
- ventinove· ordinal: 29º
- Latin
- viginti novem· ordinal: 29.
- Portuguese
- vinte e nove· ordinal: 29º
Appears in sequences
- Smallest prime power >= n.at n=27A000015
- Smallest prime power >= n.at n=28A000015
- Mosaic numbers or multiplicative projection of n: if n = Product (p_j^k_j) then a(n) = Product (p_j * k_j).at n=28A000026
- The positive integers. Also called the natural numbers, the whole numbers or the counting numbers, but these terms are ambiguous.at n=28A000027
- 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=14A000028
- Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); A000099 gives values of n where |P(n)| sets a new record; sequence gives closest integer to P(A000099(n)).at n=24A000036
- Numbers that are not squares (or, the nonsquares).at n=23A000037
- Number of positive integers <= 2^n of the form 3*x^2 + 4*y^2.at n=7A000049
- Number of positive integers <= 2^n of form x^2 + y^2.at n=6A000050
- A Beatty sequence: a(n) = floor(n/(e-2)).at n=20A000062
- -1 + number of partitions of n.at n=9A000065
- Tetranacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4) for n >= 4 with a(0) = a(1) = a(2) = 0 and a(3) = 1.at n=9A000078
- Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)Pi*n^(3/2), P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record.at n=6A000092
- Record gaps between primes (upper end) (compare A002386, which gives lower ends of these gaps).at n=3A000101
- Denumerants: Expansion of 1/((1-x)*(1-x^2)*(1-x^5)).at n=20A000115
- 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=7A000124
- Pell numbers: a(0) = 0, a(1) = 1; for n > 1, a(n) = 2*a(n-1) + a(n-2).at n=5A000129
- Number of 3-dimensional polyominoes (or polycubes) with n cells.at n=4A000162
- Lower Wythoff sequence (a Beatty sequence): a(n) = floor(n*phi), where phi = (1+sqrt(5))/2 = A001622.at n=17A000201
- a(8i+j) = 13i + a(j), where 1<=j<=8.at n=17A000202