15025
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 18662
- Proper Divisor Sum (Aliquot Sum)
- 3637
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12000
- Möbius Function
- 0
- Radical
- 3005
- Omega Function (Ω)
- 3
- 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
- 89
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Numbers k such that the continued fraction for sqrt(k) has period 37.at n=35A020376
- Partial sums of A001157: Sum_{j=1..n} sigma_2(j).at n=32A064602
- q-factorial numbers 3!_q.at n=24A069778
- Integers k such that 10^k - 33 is prime.at n=25A108364
- Positive numbers y such that y^2 is of the form x^2+(x+16807)^2 with integer x.at n=4A156713
- Square array T(n, k) = Product_{j=1..n} ( Sum_{i=0..j-1} ((k+1)^3 - (k+1))^i ) with T(n, 0) = n!, read by antidiagonals.at n=18A156882
- Conjectured positive numbers which have more than one representation (m,s) as a difference s^2 - m^5, m >= 1, s > 0.at n=32A177770
- Unitary hyperperfect numbers.at n=18A225150
- The number of permutations of length n sortable by 3 prefix reversals (in the pancake sorting sense).at n=25A228398
- Number of (n+1) X (2+1) arrays of permutations of 0..n*3+2 with each element having directed index change 1,1 2,2 -1,0 or 0,-1.at n=13A264649
- Cototient of Fibonacci(n).at n=24A278350
- Bi-unitary k-hyperperfect numbers: numbers m such that m = 1 + k * (bsigma(m) - m - 1) where bsigma(m) is the sum of bi-unitary divisors of m (A188999) and k >= 1 is an integer.at n=13A309568
- Number of sets of nonempty words with a total of n letters over quaternary alphabet such that within each word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.at n=8A340411
- Smallest integer m = b*c which satisfies (b + c)*n = m - 1.at n=23A364169
- a(n) = m is the least m = b*c > a(n-1) such that (b+c)*n = m-1 where 1 < b <= c < m.at n=23A364171