15903
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 25600
- Proper Divisor Sum (Aliquot Sum)
- 9697
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9720
- Möbius Function
- 0
- Radical
- 1767
- 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
- 128
- 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
- a(1) = 7; a(n+1) = a(n)-th composite.at n=35A025011
- "BHK" (reversible, identity, unlabeled) transform of A035353.at n=11A035355
- Number of objects generated by the Combstruct grammar defined in the Maple program. See the link for the grammar specification.at n=9A052891
- Non-palindromic number and its reversal are both multiples of 19.at n=31A062916
- Lengths of successive words (starting with a) under the substitution: {a -> aab, b -> aac, c -> ab}.at n=9A101169
- Group the triangular numbers so that the n-th group sum is a multiple of n. 1, (3, 6, 10, 15), (21), (28), (36, 45, 55, 66, 78), (91, 105, 120, 136, 153, 171, 190), ... Sequence contains n-th group sum divided by n.at n=24A114032
- Integers i such that 9*i = 25 X i, but 17*i is not 49 X i.at n=24A115811
- a(n) is the smallest positive multiple of 2n-1 that contains the binary representation of n in its binary representation and that is a palindrome when written in binary.at n=15A158789
- a(n) = (6 + 10*n + 5*n^2 + n^3)/2.at n=30A164845
- The Wiener index of the Dutch windmill graph D(6,n) (n>=1).at n=18A180578
- Number of nondecreasing arrangements of n+2 numbers in 0..3 with each number being the sum mod 4 of two others.at n=41A183906
- Numbers whose binary representation is palindromic and in which all runs of 0's and 1's have length at least 2.at n=50A222813
- Products of three distinct tribonacci numbers > 1.at n=31A274434
- Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 478", based on the 5-celled von Neumann neighborhood.at n=26A288505
- Starts of runs of 4 consecutive Gray-code Niven numbers (A344341).at n=23A344344
- a(n) is the index of the smallest n-gonal number with exactly n prime factors (counted with multiplicity).at n=16A359014
- Numbers of the form A073138(k) XOR A038573(k).at n=47A380544
- Number of rich ternary words of length n.at n=10A384371