15627
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 20840
- Proper Divisor Sum (Aliquot Sum)
- 5213
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10416
- Möbius Function
- 1
- Radical
- 15627
- 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
- 133
- 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
- Numbers that are the sum of 3 nonzero 6th powers.at n=20A003359
- Numbers that are the sum of at most 3 nonzero 6th powers.at n=37A004854
- a(0) = 1, a(n) = 25*n^2 + 2 for n > 0.at n=25A010015
- Fibonacci sequence beginning 1, 25.at n=15A022395
- Number of 5's in all partitions of n.at n=37A024789
- a(n) = (n-1)*(n-2)*(n-3) + n.at n=26A034324
- Third step in Goodstein sequences, i.e., g(5) if g(2)=n: write g(4)=A057650(n) in hereditary representation base 4, bump to base 5, then subtract 1 to produce g(5).at n=9A059934
- 53 'Reverse and Add' steps are needed to reach a palindrome.at n=5A065320
- a(1) = 1; a(n) = 1 + Sum_{i=1..n} Product_{j=i..2*i-1} (n-j).at n=12A072374
- a(n) = n^3 + 2.at n=25A084380
- Number of n X n matrices with entries {-1,0,1} that are diagonalizable over the complex numbers.at n=2A091470
- Row sums of number triangle A122851.at n=13A122852
- Number of nondecreasing integer sequences of length 6 with sum zero and sum of absolute values 2n.at n=29A158140
- Numbers n with following property: let c = nearest cube to n that is different from n and let p = nearest prime to n that is different from n. Then |n-c| = |n-p|.at n=24A163497
- Number of (n+1)X(n+1) -10..10 symmetric matrices with every 2X2 subblock having sum zero and one, three or four distinct values.at n=2A211819
- Minimal number (in decimal representation) with n nonprime substrings in base-5 representation (substrings with leading zeros are considered to be nonprime).at n=26A217105
- a(n) = 5^n + 2.at n=6A242328
- Semiprimes of the form n^3 + 2.at n=14A259189
- Number of chains in the poset of even-sized subsets of {1,2,...,n} ordered by inclusion.at n=8A260464
- Number of permutations of [n] with exactly nine (possibly overlapping) occurrences of the generalized pattern 23-1.at n=2A264468