13579
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13984
- Proper Divisor Sum (Aliquot Sum)
- 405
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13176
- Möbius Function
- 1
- Radical
- 13579
- 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
- 37
- Smith Number
- no
- Vampire 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
Appears in sequences
- Odd heptagonal numbers (A000566).at n=37A014637
- Concatenate odd numbers.at n=4A019519
- Pseudoprimes to base 84.at n=30A020212
- Numbers k such that the continued fraction for sqrt(k) has period 96.at n=38A020435
- Smallest number m with nonzero digits such that A046810(m)=n.at n=34A046813
- a(n) is the least integer that has exactly n anagrams that are primes.at n=34A046890
- Row sums of array T as in A055215.at n=30A054405
- McKay-Thompson series of class 41A for Monster.at n=50A058670
- Smallest multiple of 2n+1 with property that digits are odd and each digit is two more (mod 10) than the previous digit; or 0 if no such number exists.at n=18A062886
- a(n) = A026905(n) - A014284(n).at n=26A086741
- a(n) = 8*n^2 + 88*n + 43.at n=36A086760
- a(n) = least semiprime with factors not previously used containing integers 2n and 2n+1 as substrings.at n=18A086887
- (2n+1)-digit anti-palindromic numbers or numberdromes, whose first and last digits add to ten, second and next-to-last add to ten and so on with the central digit a 5.at n=11A093472
- Smallest available integer which fits into the repeating pattern 13579.at n=20A098758
- Heptagonal numbers for which the digital root is also a heptagonal number.at n=34A117663
- Heptagonal numbers with only odd digits.at n=7A117993
- Odd digits in increasing order.at n=30A119253
- Let T = {1,3,5,7,9,1,3,5,7,9,1,3,5,7,9, ... }; a(n) is n-th concatenation of n numbers from T.at n=4A137309
- Numerators of coefficients in series expansion of 1/(Bernoulli trial entropy).at n=38A145176
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (-1, 1, 1), (0, 0, 1), (1, 0, -1)}.at n=10A148298