14878
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 22968
- Proper Divisor Sum (Aliquot Sum)
- 8090
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7224
- Möbius Function
- -1
- Radical
- 14878
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- yes
- 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
- 45
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = p*(p-1)/2 for p = prime(n).at n=39A008837
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=45A024844
- a(n) = 2*n*(4*n + 1).at n=43A033585
- Number of partitions of n with equal nonzero number of parts congruent to each of 2, 3 and 4 (mod 5).at n=58A035591
- Number of partitions of n into parts not of the form 21k, 21k+2 or 21k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 9 are greater than 1.at n=41A035980
- Row 3 of square array defined in A047671.at n=19A047672
- a(n) = 25*n*(n + 1)/2 + 3.at n=34A061793
- Smallest number such that GCD of EulerPhi of 2 consecutive integer equals 2n.at n=42A063444
- Triangular numbers with sum of digits = 28.at n=1A068132
- Sort the digits of these triangular numbers into descending order and drop zeros to get primes.at n=22A082923
- Rearrangement of triangular numbers such that the sum of two consecutive terms is a palindrome.at n=42A082980
- Number of partitions of n such that the set of odd parts has only one element.at n=48A090868
- Numbers k such that 2^(2*(k+1)) + 2^k - 1 is prime.at n=34A105181
- Least triangular number divisible by n-th prime.at n=39A112456
- Triangular numbers for which the sum of the digits is a hexagonal number.at n=36A117309
- Triangular numbers that are products of three distinct primes.at n=40A128896
- Triangular numbers T such that T+1 is a prime.at n=44A129545
- Values of m such that A139361(n)=4m+1.at n=31A139362
- Initial term of a series of exactly n consecutive non-Niven (or Harshad) numbers.at n=17A144378
- a(n) = m*(m+1)/2, where m = floor(n^(3/2)).at n=30A185541