15928
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
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 32760
- Proper Divisor Sum (Aliquot Sum)
- 16832
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7200
- Möbius Function
- 0
- Radical
- 3982
- Omega Function (Ω)
- 5
- 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
- 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
- 53
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers n such that prime(n) mod n <= 10.at n=49A022465
- Numbers k such that prime(k) == 3 (mod k).at n=12A023145
- Number of partitions of n into parts not of the form 25k, 25k+4 or 25k-4. Also number of partitions with at most 3 parts of size 1 and differences between parts at distance 11 are greater than 1.at n=38A036003
- Least k such that k-th prime > n * k.at n=10A038606
- Values of pi(x) where x exceeds n * pi(x).at n=10A038624
- Index j of prime p(j) such that floor(p(j)/j) = n is first satisfied.at n=10A062742
- Number of 4 X n (0,1) matrices such that each row and each column is nondecreasing or nonincreasing.at n=10A086114
- Duplicate of A038606.at n=11A090974
- Number of solutions to x*frac[p(x)/x]<=Log[n] or A004648(n)<=Log[n].at n=25A099641
- Least integer k > 0 such that prime(k) - k*n is prime.at n=10A247895
- a(1)=1, a(2)=2; thereafter a(n) = a(n-1) + a(n-1-(number of even terms so far)) + a(n-1-(number of odd terms so far)).at n=41A249039
- Total number of inversions in all compositions of n into distinct parts.at n=22A271372
- Numbers k such that (292*10^k - 1)/3 is prime.at n=19A281407
- Numbers k such that Bernoulli number B_{k} has denominator 61410.at n=5A295591
- a(n) = Sum_{-n<i<n, -n<j<n, gcd{i,j}=3} (n-|i|)*(n-|j|)/4.at n=30A331775
- Numbers k such that k and k+2 are both infinitary practical numbers (A334901).at n=35A334903
- For 1<=x<=n, 1<=y<=n with gcd(x,y)=1, write 1 = gcd(x,y) = u*x+v*y with u,v minimal; a(n) = m^2*s, where s is the population variance of the values of u+v and m is the number of such values.at n=11A345725
- Number of regions in a regular n-gon with all diagonals drawn whose edges all have a different number of facing edges.at n=41A350718