39
domain: N
Properties
Digital Properties
- Digit Count
- 2
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 56
- Proper Divisor Sum (Aliquot Sum)
- 17
- 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
- 24
- Möbius Function
- 1
- Radical
- 39
- 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
- 34
- Smith Number
- no
Classification
- Natural
- yes
- Even
- no
- Odd
- yes
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
Names
- German
- neununddreißig· ordinal: neununddreißigste
- English
- thirty-nine· ordinal: thirty-ninth
- Spanish
- treinta y nueve· ordinal: 39º
- French
- trente-neuf· ordinal: trente-neufième
- Italian
- trentanove· ordinal: 39º
- Latin
- triginta novem· ordinal: 39.
- Portuguese
- trinta e nove· ordinal: 39º
Appears in sequences
- Mosaic numbers or multiplicative projection of n: if n = Product (p_j^k_j) then a(n) = Product (p_j * k_j).at n=38A000026
- The positive integers. Also called the natural numbers, the whole numbers or the counting numbers, but these terms are ambiguous.at n=38A000027
- Numbers that are not squares (or, the nonsquares).at n=32A000037
- Number of primitive n-bead necklaces (turning over is allowed) where complements are equivalent.at n=10A000046
- Symmetrical dissections of an n-gon.at n=7A000063
- Partial sums of (unordered) ways of making change for n cents using coins of 1, 2, 5, 10 cents.at n=9A000064
- Denumerants: Expansion of 1/((1-x)*(1-x^2)*(1-x^5)).at n=24A000115
- a(n) = sigma(n), the sum of the divisors of n. Also called sigma_1(n).at n=17A000203
- A Beatty sequence: floor(n*(e-1)).at n=22A000210
- Number of partitions into non-integral powers.at n=2A000263
- Remove all factors of 2 from n; or largest odd divisor of n; or odd part of n.at n=38A000265
- Number of partitions into non-integral powers.at n=4A000327
- Numbers where total number of 1-bits in the exponents of their prime factorization is even; a 2-way classification of integers: complement of A000028.at n=20A000379
- Numbers of form x^2 + y^2 + 7z^2.at n=31A000394
- Numbers of form x^2 + 2y^2 + 2yz + 4z^2.at n=35A000398
- Numbers of form x^2 + y^2 + 2*z^2.at n=37A000401
- Numbers that are the sum of 4 nonzero squares.at n=25A000414
- The greedy sequence of integers which avoids 3-term geometric progressions.at n=29A000452
- 1 together with products of 2 or more distinct primes.at n=13A000469
- Number of partitions of n into distinct primes.at n=61A000586